A Great Ship Needs Deep Waters: 14 Power Supply Units with 1000W+ Capacity

Our roundup will talk about 14 power supply units from 12 different manufacturers that have one thing in common: they all offer capacity of 1000W or higher.

by Oleg Artamonov
10/05/2009 | 11:21 AM

We are publishing test results of 14 power supplies from 12 brands ranging in wattage from 1000 to 1500 watts. We guess the scale of the test session is up to the tested products’ class.

Testing Methodology

 

Click the following link for a description of our testing methodology and equipment and a brief explanation of what the specified and tested parameters of power supplies mean: X-bit Labs Presents: Power Supply Units Testing Methodology In-Depth. If you feel overwhelmed with the numbers and terms this review abounds in, refer to an appropriate section of the mentioned article for explanation.

You can also go to our Cooling/PSU section to check out reviews of other PSU models we have tested in our labs.

We will mark the actual power consumption of three system configurations (discussed in our article PC Power Consumption: How Many Watts Do We Need?) in the cross-load diagrams. This will help you see if the PSU can meet the requirements of a real-life PC. We will also add overclocked configuration to this list in near future.

overclocked configuration to this list in near future.

Testing Participants

Akasa PowerMax AK-P100FG (1000W)

Akasa is a new name in our PSU reviews. Running a little ahead, I must confess it does not make PSUs itself. The actual manufacturer is Enhance Electronics.

The PSU comes in a large box with a carry handle. The accessories include a user manual, screws, and a power cord.

Exterior Design

The PSU has rather modest dimensions. It is a little larger than the ATX form-factor’s standard 145 millimeters, but will easily fit into any system case that you might want to install such a high-wattage PSU in. The PSU housing is painted matte black and lacks any decorative elements except for the LED near the power socket that shines green when the PSU is on and red when the PSU is off.

The Akasa PowerMax is equipped with fixed cables including:

This model is going to suit system cases with a bottom position of the PSU which have become popular due to good temperature conditions. You have to extend the CPU power cable to use regular PSUs in such system cases, but the AK-P100FG’s CPU cable is a generous 76 centimeters long.

This model has only two cables with SATA power connectors (this may be not enough to power up a RAID array built out of 4 or 5 disks because one cable goes to optical drives usually located high above) but the cables are 10 centimeters longer than standard (25 centimeters between the connectors). Still, I guess that three cables, even shorter, would be handier for users of RAIDs.

You might also cavil at being offered only two graphics card cables with four connectors. It means you can connect two top-end graphics cards without adapters. On one hand, our tests suggest that today’s games do not scale up well on more than two GPUs (and you can build even a quad-GPU subsystem out of two graphics cards by using Radeon 4870 X2 or GeForce GTX 295), but on the other hand, there are some users who pack three graphics cards into their computers.

Well, I’m just fault-finding. The selection of cables and connectors is good enough to assemble a top-end gaming station.

Interior Design

Notwithstanding the compact size, the PSU is not cramped inside. After huge-size 1000W models I have got used to, I would visually estimate the wattage rating of the AK-P100FG at 600-700 watts (running ahead, I must admit that this PSU copes with 1000W load without problems).

This must be due to a steady improvement in components. A higher efficiency means lower heat dissipation and the opportunity to install smaller heatsinks. Higher operating frequencies mean a smaller power transformer, so one 1000W transformer can be fitted within the PSU housing without being split into two 500W transformers.

The AK-P100FG does not have any of the newfangled technologies such as dedicated switching regulators at the output to produce +5V and +3.3V out of +12V. This is a rather ordinary product with dedicated voltage regulation based on magnetic amplifiers. It also has an active PFC device (such high-wattage PSUs do not come without one anyway).

The native Enhance marking can be seen in the corner of the PCB. This is an ENP-6600 series product that must be identical to the 1000W Enhance ENP-6610GA (I will discuss it along with other Enhance products in an upcoming review).

Teapo capacitors are installed on the PSU’s output. They have given no reason to worry about their quality.

Specifications

Having a total wattage of 1000W, the PSU can yield up to 840W via the +12V rail split into two “virtual” output lines. Thus, its effective output power (considering that modern computers mostly load the +12V rail) is about 900 watts.

UPS Compatibility

Together with an APC SmartUPS SC 620 this power supply worked at loads up to 370W and 340W when powered by the mains and the batteries, respectively. The pair switched to the batteries without problems. The UPS was perfectly stable.

Output Voltage Stability

The PSU easily keeps all of its output voltages within the required limits under any permissible load. Each of the three reference configurations is in the green zone meaning that the voltages do not deflect more than 2%.

Output Voltage Ripple

The output voltage ripple is within the permissible limits except for occasional spikes on the +5V rail. The oscillogram shows that the power supply’s PWM regulator works at a very high frequency of over 150 kHz.

Noisiness

The PSU is equipped with an 11-blade 135x135x25mm fan from Young Lin Tech.

The fan’s speed does not change much through most of the load range, varying from 1050 to 1100rpm and reaching a modest maximum of 1280rpm. However, the PSU is not exactly silent. You can hear it even under zero load. On the other hand, most users are going to find it very quiet.

Efficiency and Power Factor

The PSU owes its compact size and quietness to high efficiency: up to 88% at the maximum and over 80% at loads from 100 to 1000W. The power factor is excellent, too. It is never lower than 98% at loads from 300W to maximum.

Standby Source

The output voltage of the standby source boasts excellent stability, not even getting close to the limits. On the other hand, its load capacity is rather low at 3A. This is enough for modern computers but many PSUs of similar wattage allow loading the standby source by 5 or 6A.

Summary

The only fault I can find with the Akasa PowerMax AK-P100FG is that it offers rather few (for such a high-wattage PSU) cables, but this may even be a good thing for users who don’t need a lot of power connectors. Otherwise, the PSU fully complies with its specs and will not disappoint its owner. With excellent electric parameters, problem-free operation with UPSes and low noise, this power supply will be a good choice for a top-performance home machine.

CoolerMaster Real Power Pro RS-C50-EMBA-D2 (1250W)

Unlike Akasa, CoolerMaster has already taken part in our tests, yet the two companies have something in common. Like the PowerMax, the Real Power Pro is manufactured by Enhance, but based on a different, more advanced, platform. So, it will be interesting to compare the two PSUs with each other.

The actual manufacturer is indicated by the UL certificate number on the label: E166947. By the way, you can see the same number certificate on the label of the Akasa PSU.

This model comes in a rather large black-and-white box with a carry handle.

Exterior Design

The PSU is rather large. The Akasa PowerMax was designed exactly to match the 135mm fan, but this model has a few extra centimeters. You can also see a huge socket for a power cord: it is only necessary for countries with 110V power mains but will provoke some problems elsewhere, especially for users who want to connect an UPS.

The PSU has fixed power cables including:

The cables have a typical length for this class of PSUs but it is rather odd to see a modern PSU that has more connectors for PATA than for SATA drives. Most users don’t have a single PATA device in their system already and use Molex connectors for system fans only. Of course, there are various adapters available for Molex plugs, but I guess a 1250W power supply should provide everything necessary without any adapters.

Interior Design

Although there is some similarity with the Akasa PSU, this one is based on a different platform. The Real Power Pro uses two power transformers, each rated for 50% of the PSU’s total output power. There are no special advantages about this circuit design. It is a forced solution because the PSU housing could not accommodate one full-wattage transformer (to remind you, this PSU has a wattage rating of 1250W). As transformers are getting smaller thanks to higher converter frequencies, new materials for the cores and other such technical advances, dual-transformer platforms lose their ground as being too complex and expensive.

The heatsinks are larger than in the Akasa. You will see below how this affects the cooling of the PSU.

There are Teapo capacitors on the output. As I’ve already said above, they have a good reputation.

Specifications

Having a max output power of 1250W, the PSU can yield 1125W across its +12V power rail split into six “virtual” output lines with a max current of 20-28A each. The load capacity of the +5V and +3.3V rails is very high but does not bring any tangible benefits because modern computers consume no more than a few dozen watts from them.

UPS Compatibility

Together with an APC SmartUPS SC 620 this power supply worked at loads up to 430W when powered by the mains and the pair switched to the batteries without problems, but I had to reduce the load to 300W to ensure stable operation. Otherwise, the UPS would shut down in half a minute reporting overload. Thus, your UPS should have a sufficient reserve of wattage or sinusoidal output voltage in order to work normally with this power supply.

Output Voltage Stability

The PSU copes with any permissible load. None of the voltages violates the allowable limits, the +12V keeping within a 2% deflection from the nominal value.

Output Voltage Ripple

The output voltage ripple is rather high at full load but fits within the allowable range (although nearly reaching the limits on the +3.3V rail)

Noisiness

The PSU is cooled with a 135x135x25mm fan from Young Lin Tech. Having exactly the same fan, the Akasa PowerMax has smaller heatsinks. Does it mean the Real Power Pro is quieter?

Alas, it is not. The bottom fan speed (about 1100rpm, which is audible but comfortable) is only maintained until a load of 300W. Then it begins to grow up in a linear way. The PSU is very loud at loads above 600W. This again confirms my point that neither large heatsinks nor large fans, nor a high wattage rating can guarantee you silence. A lower-wattage and smaller PSU can prove to be much quieter at the same load.

Efficiency and Power Factor

The PSU is 80% efficient at a load of about 100 watts and improves up to 88% at the peak. Then, as the load grows up further, the efficiency declines steadily to 82%.

It looks like 75-80% efficient PSUs are a thing of the past. Today’s products generally have higher efficiency and the Real Power Pro is a good example.

Standby Source

The PSU barely copes with the maximum load on the standby source: at a current of 6A, its output voltage is 4.77V, the bottom limit being 4.75V.

Summary

Frankly speaking, the only reason you may want to buy a Cooler Master Real Power Pro RS-C50-EMBA-D2 is that you are absolutely sure your computer needs those 1250 watts of power. Although good in terms of electrical parameters, the PSU is a mediocre product overall. It is large and has a noisy fan. It is also unstable with UPSes and has a nonstandard socket for the power cord.

Corsair CMPSU-1000HX (1000W)

This model has been tested twice in our labs. First time the PSU had rather poor results but the problem was in the specific sample. So, I am going to show you the test results of a second sample of this PSU.

Each series of Corsair PSUs has a distinctive color. Blue is the color of the CMPSU-1000HX, so you will distinguish its box among others easily. I wish the box had a handle and could be carried about that easily, too.

Exterior Design

The PSU has a large (200mm long) housing painted matte black. There are no decorations, making the CMPSU-1000HX look restrained and demure.

Most of the PSU’s cables are detachable. There are Molex Mini-Fit Jr. connectors for them at the back panel. The connectors for graphics card and peripheral cables differ in size and color, so you can’t plug them wrong.

The cables are designed in an original way. They are flat, black and lack any color marking for different voltages and signals. Adjacent wires are joined together along the entire cable, so the cable is neater and more flexible than in the classic variant when a few individual wires are contained within a meshed nylon sleeve.

There are ferrite rings at the ends of the graphics card cables. They acts as high-frequency noise filters.

The PSU is equipped with the following cables and connectors:

Included with the PSU are:

So, there is everything you might want from a modern PSU. This model allows connecting three top-end graphics cards and a large RAID array without any adapters. As you can see there are more peripheral power cables in the kit than there are connectors in the PSU. It means the user can choose what power connectors are necessary for his particular computer. The short cable with two Molex connectors is handy as it is going to be enough for most systems (if you want such connectors at all). The CPU and graphics card cables are long enough for this price category while the HDD cables are rather too short. Their flexibility makes up for the shortness, though.

Interior Design

The CMPSU-1000HX can be instantly recognized as the monstrous “two power supplies in one housing” design developed and manufactured by Channel Well. I provided a detailed description of such PSUs, which sell under different brands, in an earlier review. Briefly, there are indeed two virtually independent 500W power supplies inside the CMPSU-1000HX, one providing +12V and +3.3V and the other +12V and +5V. Each PSU has a dedicated high-voltage section, starting from active PFC.

CWT engineers developed this design in order to release PSUs with wattage ratings up to 1500W and with more or less ATX-like dimensions. However, they are going to leave the scene soon as they are too complex. CWT has already developed a 1200W PSU with traditional design. It was discussed in our review of Ikonik power supplies.

The PSU makes use of independent step-down regulators to get +5V and +3.3V voltages out of +12V. The main power transformers only generate the latter voltage, which makes them smaller and somewhat cheaper to manufacture.

A small card of the +5V standby source hangs next to the external vent grid. This position improves the cooling of the standby source (and it becomes hot when the main part of the PSU and its fan are turned off, so the proximity of cold outside air is very good for it), but produces additional resistance to the air flow in the already cramped PSU.

Specifications

The distinguishing feature of PSUs based on this design is that the output power rails are all divided into two groups, and the combined load in each group cannot be higher than 500 watts. Thus, you can only squeeze the full 1000 watts out of this PSU if your load is ideally split into two 500W groups. Therefore, the effective output power of this PSU may differ greatly from its specification.

On the other hand, this separation ensures higher stability of the output voltages because any surges of voltage in one group cannot affect the output voltages of the other group.

Otherwise, the specifications are standard enough for this product class.

UPS Compatibility

Together with my APC SmartUPS SC 620 this power supply worked at loads up to 380W when powered by the mains. The pair was not particularly stable on the batteries. They switched to the batteries normally but then the UPS would produce characteristic gurgling sounds and shut down in half a minute, reporting overload, even at a load of only 300W.

Thus, an UPS with sinusoidal output voltage is recommended for this power supply.

Output Voltage Stability

The +12V voltage (I measured the output voltage of one of the sub-PSUs, the total load being equally distributed between them) boasts excellent stability. It does not deflect more than 1% from the nominal value. The +5V and +3.3V voltages reach a 4% deflection but do not violate the limits even at high loads.

Output Voltage Ripple

At the maximum permissible load the high-frequency ripple on the +12V rail is very low. On the +3.3V rail it is as high as the allowable limit, but that’s not a problem really.

The low-frequency pulsation is barely visible.

Noisiness

The PSU is cooled with a 7-blade 140x140x25mm fan from Yate Loon.

The fan speed is below 1000rpm at loads up to 350W and the PSU is rather quiet then. When the fan accelerates at higher loads, the speed goes up to 2000rpm, making the CMPSU-1000HX a rather noisy thing. This PSU is only comfortable for your ears at loads below 450W.

Efficiency and Power Factor

The PSU is 85% efficient at the maximum but its efficiency declines at higher loads, being barely above 80% at 970W. The power factor varies much depending on load, which is rather odd.

Summary

The Corsair CMPSU-1000HX is undoubtedly a high-quality product. However, it has a number of stronger opponents that are superior in one or another parameter. On the downside of this model are its very large dimensions, noisy fan (even at medium loads) and a very complex (and thus potentially less reliable) circuit design.

Enermax Revolution 85+ ERV1050EWT (1050W)

The Enermax Revolution series was introduced to our readers in our earlier review. It is interesting for its good characteristics as well as technologies employed. Enermax claims this series incorporates all cutting-edge innovations ready for mass production, resulting in a progressive platform that will serve the company for the next few years.

The PSU comes in a big box with laconic design. The developer seems to suggest that this is a very serious product.


Exterior Design

The PSU itself is designed in an original way, though. It is painted a rough (not just matte but really rough) gray paint and has a separate red plate around the fan. The edges of the case are rounded off. All of this makes the Revolution series different from standard PSUs.

Take note of the fan frame: its edges are rolled in to reduce the gap between the fan body and the PSU case. The manufacturer says this solution helps reduce the noise by 1-2dB.

Most of the cables are detachable. There are two rows of connectors in the PSU for them. Take note of the size and pin count of the connectors for graphics card cables (the red ones). You can attach two graphics card connectors to each, for a total of four top-end graphics cards. The PSU is equipped with the following cables and connectors:

Included with the PSU are:

So, there is a total of eight connectors for graphics cards (plus two more connectors on the PSU!) and 16 connectors for SATA drives. That’s rather too much for a home computer, but people who build powerful systems for GPGPU applications may be interested in this PSU.

Interior Design

I will refer you to the above-mentioned review for details about the circuit design features of the Enermax Revolution series. Here, I’ll just give you a few basic facts. The main regulator is based on two transformers working alternately: the PWM controller is sending impulses to one and then to another. This solves the problem of load balancing and allows to get any output power from 0 through 1050 watts from this PSU. The main regulator yields +12V only whereas +5V and +3.3V are produced by means of additional independent regulators residing on a card at the back panel of the PSU.

Funnily enough, the marking of the PWM controller is carefully rubbed out in my sample of the PSU although its name and operation should not be a secret for those who read our review of the 850W Revolution. You can also find them in an article published by Texas Instruments (the developer of the controller) a few years ago, so I don’t think that’s a secret for Enermax’s competitors, either.

Specifications

The PSU can yield almost all of its 1050 watts of maximum output power via the +12V rail, so its effective output power equals its specification. That’s perfectly normal considering the circuit design: all of the PSU’s voltages are produced from +12V by means of additional regulators, so the +12V rail must have the same load capacity as the whole PSU.

UPS Compatibility

Together with an APC SmartUPS SC 620 this power supply worked at loads up to 390W when powered by the mains and up to 350W when powered by the batteries. The UPS switched to its batteries normally and was stable. Thus, this power supply is compatible with UPSes with trapezoidal output voltage. And there will be no problems at all with top-end models with sinusoidal output.

Output Voltage Stability

The output voltages are almost ideally stable, deflecting no more than 4% through the entire range of permissible loads. Only one of our three reference configurations does not fit into the “green” zone. Enermax puts a special emphasis on the ability of this PSU to work under any load from zero to maximum. As you can see, the cross-load diagram is indeed built from zero along both axes.

Output Voltage Ripple

The output voltage ripple at maximum load is within the permissible limits and very low on the +12V rail.

Noisiness

The PSU is cooled with a 135x135x25mm fan from Globe Fan.

The fan starts out at a very modest speed of only 660rpm. The speed grows up at higher loads, but only reaches 1000rpm at a load of 700W or higher. Besides, the PSU has a rather agreeable noise spectrum, without any irritating tones, so it is comfortable enough even at full load and 1500rpm. Overall, the Revolution is a very quiet PSU.

Efficiency and Power Factor

The efficiency is very good: over 80% at any load from 100W and higher and 91% at the maximum. The PSU is as high as 87% efficient even at full load.

Standby Source

The standby source has a load capacity of 5A and copes with the job easily. The output voltage is higher than 4.9V, the allowable minimum being 4.75V.

Summary

The only problem I can find in the Enermax Revolution 85+ is that it is rather large. There are already many 1000W units that are 3-4 centimeters shorter. However, such high-wattage PSUs are not usually installed into compact system cases while in its other parameters the Revolution is one of the best models we’ve ever tested in our labs, offering stable voltages, high efficiency, quietness and a rich selection of cables and connectors. This PSU is going to be an excellent choice for a top-end gaming computer as well as for a workstation, including GPGPU platforms.

Gigabyte Odin Pro GE-MK20A-D1 (1200W)

Gigabyte has taken part in my earlier PSU tests and the last time this brand was represented by an interesting model that could report detailed data about the current power consumption. Today’s model is more trivial but has a wattage rating of 1200W.

The PSU comes in a pretty box that has a carry handle.

Exterior Design

The PSU is rather large at over 200 millimeters of length and is painted matte black. The only embellishments are the On/Off button with red highlighting and the protruding letters “Gigabyte” on the side panel.

The PSU is modular. Some of its cables are detachable. You can connect them to the connectors on the back panel that differ in size, position of the key and color.

The mainboard power cable has a rubber knob that does not help in any way, especially if there are tall components near the mainboard’s power connector.

The PSU is equipped with the following cables:

Included with the PSU are:

I guess there are enough connectors here but the ten available SATA power plugs might be split into three cables with three or four connectors on each, which would be handier in most cases.

Interior Design

The interior of the Odin Pro looks familiar: it is the dual power supply from Channel Well, similar to the above-discussed Corsair CMPSU-1000HX. Corsair’s model had two 500W sub-PSUs whereas the Odin Pro has two 600W sub-PSUs. For more details about this design you can refer to the description of the CMPSU-1000HX above or to our special review dedicated to such monsters.

Specifications

The specifications are standard for this series of Channel Well power supplies. Formally, the PSU can yield its full output power via the +12V rail, but the load must be ideally halved between its two sub-PSUs for that. Anyway, a 1200W power supply is going to have a large reserve of wattage in any computer.

I should also note that the words “Design by GIGABYTE in Taiwan” look somewhat odd on a label of a typical PSU developed and manufactured by Channel Well and selling under half a dozen brands.

UPS Compatibility

Together with an APC SmartUPS SC 620 this power supply worked at loads up to 350W when powered by both the mains and the batteries, but the UPS was not very stable. You should choose an UPS with a large reserve of wattage or, better yet, with sinusoidal output voltage for this power supply.

Output Voltage Stability

The +12V voltage is ideal, fitting within a 1% deflection from the nominal value. The +5V is just a little worse and the +3.3V does not exceed the allowable limits, either.

Output Voltage Ripple

The output voltage ripple is within the permissible limits at full load.

Noisiness

The PSU is cooled by a 5-blade 140x140x25mm fan (Yate Loon D14BH-12).

The fan speed remains constant until a load of 500W. The PSU is average in terms of noisiness then. It won’t satisfy a lover of silence but most users are going to find it acceptable. Then, the speed grows up along with the load, making the PSU noisy at 800W.

The Odin Pro is better than the above-discussed 1200W Cooler Master in noisiness. If compared with the Corsair CMPSU-1000HX, the Odin Pro is somewhat louder at low loads, but the Corsair’s fan begins to accelerate sooner as the load is growing up.

Efficiency and Power Factor

The PSU is 88% efficient at the maximum but drops to 83% under higher loads. This drop is smaller than with the Corsair power supply.

Standby Source

The standby source is rated for a current up to 3.5A and indeed copes with that load. Its minimum output voltage is 4.8V, the allowable minimum being 4.75V.

Summary

The Gigabyte Odin Pro GE-MK20A-D1 is not a poor power supply, of course. Its high wattage, good electric parameters and acceptable noisiness make it a good choice for a powerful gaming computer. The only fault I can actually find with the Odin Pro is that it lacks a special feature that would make it different from its opponents, especially those many other PSUs based on the same platform from Channel Well.

Hiper M-1000ME (1000W)

Hiper is not a frequent visitor of our labs although its power supplies are widespread and popular among end-users. I will try to make my amends to the company now.

The PSU box is designed in Hiper’s style: the meshed pattern on the front panel resembles the mesh Hiper’s PSUs are usually made from.

Exterior Design

The meshed panels are actually a questionable solution. The position of the heatsinks inside the PSU is anyway optimized for a lengthwise flow of air. And I don’t think the cooling of the PSU improves from the fact that some of the hot air goes back into the system case.

The number of vent holes in the external panel of the PSU is small and its top is even blank completely, while a considerable portion of the bottom part of that panel is occupied by the mains socket and the On/Off switch. Perhaps this is done for the sake of unification with Hiper’s PSUs that have an integrated USB hub whose ports are installed in the top part of the panel, but I guess the manufacturer shouldn’t have reduced the airflow in such a way.

The cables are fixed but go out of the PSU housing in a few groups, each group through its own hole. This helps reduce the mess of cables somewhat but does not affect the ease of assembly.

The PSU is equipped with the following cables and connectors:

This is a standard selection and I don’t see anything to complain at. It is good that the cables with HDD connectors differ in length as you can choose what cable suits your particular system case. The connectors for PATA drives are single: Hiper seems to imply that this type of cable may only be necessary for but a single device. The PATA standard having become outdated, there is no need to put a bunch of connectors on each power cable.

Interior Design

The PSU is a rather typical modern model. A few other makers use the same circuit design and component layout. I don’t have any direct evidence as to what company makes the M-1000ME for Hiper, but I have reasons to think that it is Sirtec whose products can be found under the brands of Chieftec and High Power as well.

The PSU features dedicated voltage regulation based on magnetic amplifiers.

Specifications

The M-1000ME has standard characteristics. Having a max output power of 1000W, it can yield 900W via its +12V rail which is split into four virtual output lines with different current limitations. The peak output power of 1100W must be the load the PSU can work under for a limited period of time, usually no more than 1 minute.

UPS Compatibility

Together with my UPS this power supply worked at loads up to 375W when powered by the mains. But when powered by the batteries, the pair was only stable at loads of 250W or lower. Thus, you need an UPS with a much larger wattage rating or with sinusoidal output voltage for this power supply.

Output Voltage Ripple

The PSU boasts excellent voltage stability at any permissible load. The +12V rail is always within 3% from the nominal value whereas the +5V and +3.3V rails deflect by no more than 4%.

Noisiness

The PSU is cooled by a 135x135x25mm fan from Globe Fan. One fourth of the fan is covered with a celluloid triangle in order to increase the pressure at the back of the PSU. It is from there that the air should go into the front part of the PSU case and leave it. Without that, the cooling of the back of the PSU would be somewhat worse.

The PSU is rather quiet at loads up to 300W but then begins to accelerate its fan in a linear way. It becomes really noisy at loads of 600W and more – and most of the noise is produced by the air passing through the perforated side panels.

Efficiency and Power Factor

The maximum efficiency is 87%, which is average for today’s PSUs. The power factor is surprisingly low, not reaching 0.9 even at a load of 200W.

Standby Source

The standby source is rated for a current up to 3A and copes with that load well. Its output voltage is never lower than 5V.

Summary

The Hiper M-1000ME can actually be described as the above-discussed model from Gigabyte. It is good but lacks a special feature, something that would provoke you to look for this specific model among the numerous alternatives. Good electrical parameters, average noise comfort and a standard selection of cables and connectors. That’s all I can say about the Hiper M-1000ME.

Kingwin Mach I ABT-1000MA1S (1000)

Kingwin debuts in our reviews with this model.

The PSU comes in a compact and handy box with a carry handle.

Exterior Design

As opposed to Hiper, the developer here is generous as to the vent holes in the external panel of the PSU. I wouldn’t call it a distinguishing trait, though. The PSU is overall similar to most other models of its class.

The Kingwin has detachable cables that are connected to the PSU via threaded industrial connectors rather than popular Molex Mini-Fit Jr. The connectors’ pins are not separated, so an accidental touch of a metallic object may provoke a short circuit. Therefore the connectors are covered with silicone caps (shown in the bottom of the photo). The connectors have a different number of pins, so you can’t connect a wrong cable to them.

When a cable is connected, a blue rings start to glow around the corresponding connector. This is a rather beautiful and original solution for system cases with a transparent side panel. The fan has blue highlighting, too.

The PSU is equipped with the following cables and connectors:

Included with the PSU are:

This is a perfectly standard selection of cables, but I wish there were one extra cable with SATA connectors included into the kit. The user would be able to choose what is necessary for his particular system then. Considering that one SATA cable is usually taken by the optical drive, such a cable might have only two or three connectors.

Interior Design

The PSU has a standard circuit design with one power transformer, active PFC, and dedicated voltage regulation based on magnetic amplifiers.

The PSU employs Pce-tur capacitors. They are average quality components.

Specifications

The specs are perfectly standard for a modern 1000W power supply. The PSU can yield almost all of its output power via the +12V rail.

There is a funny sticker on the PSU showing the dependence of the fan speed on temperature as a graph. This “new design” is long used in all PSUs from all brands. And it is also unclear what temperature is shown in the graph. The controller’s thermal sensor is usually attached to one of the PSU’s heatsinks and it is quite normal for a heatsink to be 50 or 60°C hot. And even if this is the air temperature, I don’t think it can be lower than 25-30°C inside a computer that consumes so much power whereas the graph starts, most optimistically, from zero!

UPS Compatibility

Together with my APC SmartUPS SC 620 this power supply worked at loads up to 340W when powered by the mains and 330W when powered by the batteries. They switched to the batteries normally and the UPS was stable.

Output Voltage Stability

The PSU delivers absolutely stable voltages. The voltages do not deflect more than 4% at any load (and the +5V and +12V voltages keep within a 3% deflection even).

Output Voltage Ripple

The Kingwin Mach I has a rather strong high-voltage pulsation on the +12V rail, yet it is within the permissible limits.

Noisiness

The PSU is cooled by a 135x135x25mm fan from Globe Fan. A part of the fan is covered with celluloid film with perforation on the right – that’s not a good solution in terms of noisiness.

The low speed of the fan makes up for that, though. The fan is rotating at only 830rpm even at a load of 700W, making the Mach I a very quiet power supply. Of course, the downside is that the temperature of the air passing through the PSU may grow by as many as 18°C. I didn’t spot any overheat-related problems during my tests of this PSU, though.

Efficiency and Power Factor

The efficiency is quite normal for this class of PSUs: it goes higher than 80% at a load of 140W, reaches a maximum of 87% and declines to 83% at full load. The power factor is higher than 0.99 through most of the diagram.

Standby Source

The standby source is rated for a current up to 5A but barely copes with the job. The voltage bottoms out to the allowable minimum of 4.75V under full load.

Summary

Summing it up, the Kingwin Mach I is a good high-wattage power supply that is quieter than most of its opponents and has beautiful connectors for detachable cables. Its electrical parameters are all right. So, if you’ve got a system case with translucent side panel and are fond of blue highlighting, you may like the Mach I.

OCZ Z Series Z1000M (1000W)

Having started as a maker of memory modules and coolers, OCZ Technology has been constantly expanding its scope in the last couple of years. Particularly, it has begun to produce power supplies. Today I will discuss the 1000W model from the Z series, and we will also publish a review of a few affordable power supplies from OCZ, with wattage ratings of about 400W, in near future.

The PSU comes in a medium-sized black-and-yellow box.

Exterior Design

The Z1000M is one of the two smallest products in today’s tests, the Akasa PowerMax being the other one. Its dimensions are actually determined by the size of the cooling fan.

Like in Enermax models, the PSU case is rolled in near the fan to reduce the gap between the fan and the panel. This should lower the noise produced by the fan.

The PSU is modular and offers eight connectors for detachable cables. It is not good that the 6-pin connectors for graphics card and peripheral cables are different colors and voltages, but have identically positioned keys. It means you must be very careful when connecting your components to this PSU as it offers neither mechanical nor electrical protection against incorrect connection of the power cables, which may, for example, destroy your HDDs.

The PSU is equipped with the following cables and connectors:

Included with the PSU are:

Although there are both 8- and 6-pin connectors for graphics cards in the PSU, the included cables all had one 8-pin and one 6-pin end. Hopefully, it is only a problem with the accessories to my sample of the PSU and the Z series will come to shops with a correct selection of cables.

It is good that there are more SATA than PATA power cables. The four SATA cables will be most suitable for RAID arrays. The PSU also allows to connect up to three top-end graphics cards without power adapters.

The only thing that I don’t quite grasp – not only in OCZ products – is that there are two fixed CPU power cables. There are very few mainboards with two connectors (mostly dual-processor server-oriented models), so most users won’t use one of these cables. Why not make it detachable then?

The detachable cables come neatly packed into a nice pouch.

Interior Design

The interior design is typical of many modern PSUs. The power components are distributed among three independent heatsinks. There are no noticeable innovations in the Z series. It is an ordinary PSU with one transformer, active PFC and dedicated voltage regulation on magnetic amplifiers.

The PSU is manufactured by Sirfa which had been a Sirtec fab before 2008 but now is an independent venture.

Specifications

The PSU’s specs indicate no splitting of the +12V rail into “virtual” output lines. This has no effect on stability but solves the possible problem when the PSU might shut down due to overload on one of the individual +12V lines. The PSU can yield its full 1000W via the +12V rail, so its effective output power equals the specified value.

UPS Compatibility

Together with an APC SmartUPS SC 620 this power supply worked at loads up to 415W when powered by the mains. They switched to the batteries normally but were not stable even at 300W then. Therefore, I’d recommend a UPS with sinusoidal output voltage for the Z1000M.

Output Voltage Stability

The +3.3V voltage goes beyond the permissible 5% limit under high load. On the other hand, you won’t have such load distribution in modern PCs which mostly consume from the +12V rail. This is indicated by our three reference configurations: with each of them the voltages stay within 2-3% from their respective nominal values.

Output Voltage Ripple

There are periodic spikes of voltage on the +3.3V rail that violate the permissible limit, but that’s not a big problem. The +5V voltage ripple is within the allowable limits. On the +12V rail the voltage ripple is very low although this rail has over 80% of the total load in the test.

Noisiness

The PSU is cooled by a 135x135x25mm fan from Globe Fan. About a quarter of it is covered with a celluloid triangle as in the Hiper model produced by Sirtec. So, the kinship of the two companies can be observed in small things, too.

The fan starts out at 960rpm and reaches 1000rpm at a load of 650W. Thus, the Z1000M is somewhat quieter than most of the PSUs in this review, even though not by much.

Efficiency and Power Factor

It is a second model out of 14 whose efficiency is higher than 90%. The peak efficiency is 91.7%. And at full load the PSU is 87.7% efficient. Thus, the OCZ Z1000M is even a tiny bit better than the Enermax Revolution 85+ that has been the best PSU in this test among all we have ever tested and also the only model to be more than 90% efficient.

So, the OCZ is quite deservedly certified to comply with the 80 PLUS Gold standard. Its power factor is somewhat worse, though. It varies from 90 to 95% through most of the diagram.

Standby Source

The standby source of the Z1000M is rated for a current up to 6A. Its voltage bottoms out to 4.9V under full load, which is much higher than the permissible minimum.

Summary

Although we didn't find any outstandingly unique features, OCZ has produced a very good power supply. Quiet and stable, it offers plenty cables and connectors and easily delivers its specified output power.

It should be noted that the OCZ Z series is the second PSU series (after the Enermax Revolution) to show an efficiency of over 90% in my tests. This level is going to be the goal for many makers now just as they all struggled to reach the 80% mark a few years ago. That’s how fast it goes as I can even recall those times when a 70-75% efficient PSU was considered mainstream.

SilverStone Strider SST-ST1200 (1200W)

SilverStone is represented with three models in this review. Will this give it more chances against the opponents in today’s comparison?

The 1200W Strider comes first. The company’s website classifies it as “Silent” and I will check this claim out shortly.

Exterior Design

The distinguishing feature of the Strider’s exterior is the nonstandard mains socket that is rated for high load currents. It is only necessary for regions with 110V mains because the current is twice lower at the same wattage in 220V mains.

The Strider SST-ST1200 looks suspiciously similar to the above-discussed CoolerMaster Real Power Pro RS-C50-EMBA-D2.

There is one dramatic difference, though. SilverStone engineers decided to make all cables detachable without exception. At first glance, it may seem unclear who might ever need a power supply unit without a mainboard cable, for instance. However, everything becomes clear once you go the official web-site where you can purchase a set of short cables (only 35 cm long) for those who would like to put together a very powerful system inside a compact case.

The PSU has 11 Molex Mini-Fit Jr. connectors that differ in size and the position of the key to prevent wrong connection.

The PSU is equipped with the following connectors:

Included with the PSU are:

Users of system cases in which the PSU is located at the bottom are going to appreciate the long length of the CPU cables. The connectors on the peripheral power cables are placed at a big distance from each other. Still, I wish again there were three SATA cables in the kit.

Interior Design

The interior design is familiar to me. The PSU is manufactured by Enhance and is similar to the above-discussed CoolerMaster in its circuit design. No wonder they resemble each other externally. The Strider uses a dual-transformer design with dedicated voltage regulation based on magnetic amplifiers.

Teapo capacitors are installed at the PSU’s output.

Specifications

Having a total output power of 1200W, the PSU can deliver 1125W via the +12V rail split into six virtual output lines. Take note that the lines differ in load capacity and the sticker next to the PSU connectors shows what line goes there. Oddly enough, only three lines, with a combined current of 60A (20A each), are allotted to graphics cards. Thus, you can only provide 720W of power to your graphics cards unless you use adapters. It is PCI Express power lines that usually have the highest load capacity in other PSUs.

UPS Compatibility

Together with my APC SmartUPS SC 620 this power supply worked at loads up to 380W and 310W when powered by the mains and batteries, respectively. They switched to the batteries normally and the UPS was stable. Thus, this power supply can work with non-sinusoidal input voltage if the UPS has a sufficient reserve of wattage.

Output Voltage Stability

The +12V rail yields an ideally stable voltage that deflects no more than 2% from the nominal value at any load. The +5V voltage goes beyond the permissible 5% deflection at high loads on the respective rail, but the +5V rail does not have to work under such loads in today’s computers. You can see this in our diagram where the three reference configurations all fit into the zone where none of the basic voltages deflects more than 3% from the ideal level.

Output Voltage Ripple

There are short spikes of voltage on the +5V and +12V rails at full load, but the voltage ripple is overall within the permissible limits.

Noisiness

The PSU is cooled by a 135x135x25mm fan from Young Lin Tech Co.

The fan is rotating at a constant speed of 950rpm until a load of 750W, making the PSU rather quiet. When the load grows higher, the speed is increased, reaching a maximum of over 1700rpm. The fan becomes very loud but you can hardly load a 1200W power supply so much in practice.

Thus, although the Strider SST-ST1200 is just a little quieter than average, it is much better than the Cooler Master Real Power Pro in this respect.

Efficiency and Power Factor

The Strider does not set any records in this test. It is 88% efficient at the maximum and 80% efficient at full load. This is just a good result.

Standby Source

Although the manufacturer rates the standby source at up to 6A, the latter can only deliver 5A. The voltage plummets suddenly when the current is higher than 5A. This may be a problem of the specific sample of the PSU because the standby source of the similar unit from CoolerMaster coped with 6A load.  

Summary

Although the Strider SST-ST1200 seems to be based on the same platform from Enhance as the Cooler Master Real Power Pro RS-C50-EMBA-D2 discussed earlier in this review, SilverStone’s product is obviously better in its consumer properties. It is quieter in the first place. Besides, the Strider comes with detachable cables, which is handy because a 1200W power supply has a very thick and heavy bunch of cables that is quite inconvenient even in a roomy system case.

I did not spot any serious defect in the SST-ST1200. As for minor drawbacks, it has high voltage ripple at full load (by the way, the Real Power Pro had a completely different shape of that ripple, which is one more small difference between the electronics of these two models that you can’t see with an unaided eye) and its standby source cannot deliver the promised 6A to the load.

SilverStone Strider SST-ST1500 (1500W)

The next model from SilverStone has the highest wattage rating among all PSUs in this review and comes from the Strider series, too.

Exterior Design

The PSU is large (the picture on its box rather shows the above-discussed SST-ST1200 which is somewhat smaller). The power cord is connected to a nonstandard socket, the same as in the previous model, which may provoke problems for some buyers.

All cables are detachable, which allows putting together a very powerful system inside a compact case. In this case you can purchase separately a special set of short cables as we have just described in the SST-ST1200 review on the previous page.

The PSU is equipped with the following connectors:

Included with the PSU are:

The cables are long and there is a whole dozen of SATA power plugs. Anyway, it is the Enermax Revolution 85+ that remains the leader in this respect as it offers more cables and more connectors and more places to connect them to the PSU. With the Strider, if you need more than nine SATA power plugs, there will be no place left for attaching PATA cables. Even the 1000W OCZ Z series model has 12 SATA power plugs and a free place for a cable with PATA connectors. Thus, the Strider SST-ST1500 is good but not the best in this respect.

Interior Design

All power supplies of such wattage I have tested so far were manufactured by Channel Well. The Strider SST-ST1500 is the first exception as it was developed by Enhance. Its interior resembles the above-described Strider SST-ST1200, also manufactured by Enhance, but the platforms are actually different.

The Strider is more conventional than CWT’s power supplies that actually consist of two power supplies in one housing. Here, we can see two power transformers working in sync in one power converter. The PSU does not employ DC-DC converters to produce +5V and +3.3V voltages out of +12V, although such converters have already become popular in top-wattage models. Instead, it uses traditional dedicated regulators based on magnetic amplifiers.

Electrolytic capacitors from Teapo are installed at the output. They enjoy a reputation of high-quality components.

Specifications

The PSU’s 12V rail is split into as many as eight “virtual” output lines, 25A each. Its full load capacity is as high as 1320W. The load capacity of the +5V and +3.3V rails is very high, too, even though it is going to be uncalled for by today’s +12V-oriented computers.

UPS Compatibility

Together with an APC SmartUPS SC 620 this power supply worked at loads up to 422W when powered by the mains. They switched to the batteries normally but the UPS would report overload and shut down at 200W or more. Thus, you need an UPS with sinusoidal output voltage for this power supply. Most of high-wattage UPSes are such, though.

Output Voltage Stability

My tests were limited to the capabilities of our testbed which are somewhat more modest than those of the PSU. The testbed can produce a load up to 1300W: up to 1100W for the +12V rail and up to 200W for the +5V and +3.3V rails combined.

The +12V rail boasts superb stability as its voltage remains within a 2% deflection even at very high loads. The +3.3V voltage is somewhat worse. The +5V voltage shows the same problem as we have seen with the SST-ST1200: it bottoms out below the permissible minimum of 4.75V at high load. But as I have noted many times already, that’s not a problem for modern computers which consume no more than a few dozen watts from the +5V rail (this voltage powers HDDs and feeds the mainboard a little whereas CPUs and graphics cards depend on +12V).

Output Voltage Ripple

At a load of 1300W (the maximum load our testbed can produce) the oscillograms of the high-frequency pulsations look splendid. The voltage ripple is much below the limit on each rail and there are no short spikes. It means that the capacitors at the PSU’s output are high quality and properly selected.

Noisiness

This PSU is cooled by a 135x135x25mm fan from Young Lin Tech Co.

Its initial speed is 830rpm and the fan only begins to accelerate at a load of 950W. That’s an excellent result that makes the Strider SST-ST1500 a truly quiet power supply.

Efficiency and Power Factor

The PSU is third in efficiency in this review behind the OCZ Z series and the Enermax Revolution 85+, stopping just short of the 90% mark. At a load of 1300W the efficiency declines to 84%, which is very good, too.

Standby Source

The standby source easily copes with its job: its output voltage is 4.86V at a current of 6A, which is higher than the permissible minimum of 4.75V.

Summary

Strictly speaking, it would be incorrect to directly compare the SilverStone Strider SST-ST1500 with the other tested PSUs because it is the only one to have a wattage rating of 1500W. All PSUs of that wattage I have tested so far were based on a rather complex and expensive platform developed by CWT. The Strider is based on a different platform and surpasses them in circuit design as well as in consumer properties. It is quieter, more stable, and does not have any load balancing requirements. So, if you feel like your computer needs 1500 watts of power, you should consider the SilverStone Strider SST-ST1500 in the first place.

SilverStone Zeus ZU1200M (1200W)

SilverStone markets its Zeus series as industrial class solutions. Let’s see in what aspects they differ from the Strider series.

Exterior Design

The specific interior design of this PSU can be seen even without taking its cover off: the electronics reside on two PCBs facing each other. Where is the cooling fan then? This component layout makes it impossible to install a 120mm fan whereas a classic 80mm fan is nowhere to be seen at the front grid.

The answer is simple: the fan is at the back. A PSU is actually a metallic box with vent holes in its two butt-ends, so there is no difference between the two possible positions of the fan. The air will anyway have to go through the entire interior along the heatsinks.

As opposed to the Strider’s series, the PSU’s cables are fixed. The interior design and cooling system do not allow to implement detachable cables: there is no place to fit the connectors in.

The Zeus ZU1200M is equipped with the following cables:

It is good that the cables are long. The selection of connectors is rather too modest. You can connect only six SATA drives to this PSU, which is too few for a 1000W model. And there are only two 6+2-pin connectors for graphics cards in the three pairs (they should be counted in pairs since modern graphics cards are powered by two connectors).

Interior Design

There are indeed two PCBs, facing each other, in this power supply. This is an unusual component layout as it is rather too complex and expensive. The choice of cooling fans is limited to 80mm models and low-profile components have to be used: capacitors, transformers and heatsinks of each PCB have only half the total height of the PSU.

The first PCB is about high-voltage circuitry: a filter, an input rectifier, active PFC.

The second PCB carries a power transformer, rectifiers, smoothing capacitors and secondary DC-DC converters. Despite the high wattage of this PSU, it has only one transformer that yields one voltage, +12V. The +5V and +3.3V voltages are produced from +12V by means of dedicated DC-DC converters located on small individual cards (you can see them in the top of the photo).

SilverStone tried to conceal the name of the real manufacturer but didn’t do that carefully enough. You can read the words “Impervio Electronics” through the smudge of black paint on the PCBs. This is the name of a Taiwanese company that was founded in 2006 and develops top-end PSUs with high wattage, hot swap feature, etc. By the way, Enermax bought a 75% share of Impervio Electronics in May 2009.

Specifications

The specs are typical for this product class except that the +12V rail is split into six “virtual” output lines with a load capacity of 17A (204W) each. In such high-wattage PSUs some of the lines usually have a load capacity of about 25A because today’s dual-processor graphics cards can consume over 200W under load, which is more than those 17 amperes.

The user manual says that the individual current limitations for each separate line can be just turned off. However, the appropriate switch is hidden under a sticker that reads “Warranty void if removed”.

This may be due to the small size or position of the switch near other components on the PCB. A careless movement with a screwdriver may damage the switch or the PCB. Of course, the manufacturer might have some other reason to hide it but as warranty becomes void after my tests anyway I risked and turned the splitting of the lines off. The PSU worked well then and I could test it on our testbed with two 46A instead of six 17A lines.

UPS Compatibility

Together with an APC SmartUPS SC 620 this power supply worked at loads up to 340W and 320W when powered by the mains and batteries, respectively. They switched to the batteries without problems and the UPS was stable. Thus, this PSU should have no problems working with UPSes.

Output Voltage Stability

It looks like a family trait of all SilverStone power supplies that their +5V voltage bottoms out at high load. On the other hand, this voltage only goes out of the permissible limits at loads that can hardly occur in a modern computer whereas the +12V rail, which is loaded the most, is very stable, keeping its voltage within a 2% deflection.

Output Voltage Ripple

At full load the output voltage ripple on the +5V rail is as high as the permissible limit. On the +12V and +3.3V rails the voltage ripple is considerably lower than the limit.

Noisiness

The PSU is cooled by an 80x80x25mm fan from Sanyo Denki.

The fan speed depends directly on load and the PSU proves to be rather noisy even at 350W.

Unfortunately, the PSU would shut down due to overheat at a load of 1010W during this test. Later on, I read a document from the SilverStone website and learned that thermal sensors had been misconnected in one batch of Zeus power supplies. The user is supposed to open the PSU up and correct that. As I found the document after I had done my tests, I could not check this solution out in practice.

Efficiency and Power Factor

The efficiency is far from high, not reaching 85% even. It drops below 80% at full load.

Standby Source

The standby source is rated for a current up to 4A and copes with the job. Its output voltage is never lower than 4.9V.

Summary

I did not find the SilverStone Zeus ZU1200M to be any better than the other products from the same company. The quality of the Zeus is up to the promised industrial level, but the Strider is just as good. The consumer properties of the Zeus are not quite up to today’s requirements. It is too noisy and not very efficient.

Tagan BZ Series TG1100-U88 (1100W)

Tagan’s BZ series is interesting for including a few models with ESA support. Nvidia has proposed the ESA protocol for the various components of a computer to report their status. Thus, ESA-compatible power supplies have USB interface and can report current voltages and loads on different power rails.

I won’t discuss ESA today because I’ve got an early BZ series model for my tests. It doesn’t support ESA.

Exterior Design

The PSU looks ordinary enough from this point of view, but you can see a protective silicone cap on the On/Off switch (I don’t understand the purpose of this protection) and the text “+12V Auto Turbo Switch”. The latter represents an attempt of Tagan’s marketing department to reconcile two irreconcilable things – the presence and absence of “virtual” lines on the +12V power rail. I can remind you that these lines are produced by means of protection that turns the PSU off not only on reaching a certain overall load but also on reaching a certain current on specific connectors. This improves safety, but a situation is possible when the protection is triggered on due to one overloaded line although the PSU on the whole still has more than enough of output power. Therefore some manufacturers remove such protection altogether or make 6 or 8 lines so that each heavy consumer could have its own line (if one line is shared by two such consumers, overload is more likely). Others increase the load capacity of each line from 18A (as required by the EN-60950 safety standard which had provoked the very existence of such “virtual” lines) to 22-30A.

Tagan’s marketing people seem to believe that multiple “virtual” lines contribute to higher stability and wattage (as you can learn from the previous paragraph, this is not true) and have been unable to give them up altogether. As a result, they have introduced an auto-off protection system: when the current is lower than the threshold, the protection works. As soon as the current is as high as the threshold, the protection is turned off and all the virtual lines join into one! In practical terms, it means that the PSU has no “virtual” lines with individual protection from overload.

The back panel of the PSU resembles the above-discussed model from Kingwin. The connectors for detachable cables are designed in a similar way (although the connectors themselves are somewhat different).

Indeed, when the PSU is working, the occupied connectors are shining in bright colors (the Kingwin has blue highlighting only). This pretty sight should be appreciated by users of system cases with translucent side panel.

The PSU is equipped with the following cables and connectors:

Included with the PSU are:

Tagan offers a nice selection of connectors. At last we see a power supply with a minimum of obsolete and unused connectors for PATA drives. Users who still have a lot of PATA disks can connect them using the included adapters. In fact, I wouldn’t mind if one of the detachable PATA cables were replaced with a SATA one.

The PSU has a special grounding wire that can be attached to any screw of your system case. If you securely fasten the PSU with screws to your system case without any insulating pads, this wire won’t be necessary.

The peripheral power cables are nylon-sleeved. The graphics card cables are hidden into a thick, stiff and unhandy tube and have ferrite rings that act as high-frequency noise filters.

Interior Design

The PSU only differs from other of its class with the mirroring position of the PCB: the low-voltage section is in the right of the photo and the high-voltage section is on the left. They have the opposite positions in most other PSUs. This may affect the ease of assembly, depending on the specific system case.

Although I don’t have complaints about the assembly quality in general, the electrolytic capacitors soldered to the card with connectors for detachable cables are not neat. They look as if the manufacturer had not planned them to be there.

Specifications

According to the label, the PSU has six “virtual” +12V lines each of which can deliver up to 20A for a total of 80A. But as I have written above, the +12V Auto Turbo Switch technology turns the protection off if any line is overloaded, thus joining all the lines together.

I can’t say anything about the other parameters of the PSU. The specs are normal and typical of today’s PSUs.

UPS Compatibility

Together with my APC SmartUPS SC 620 this power supply worked at loads up to 370W when powered by the mains but was not stable when powered by the batteries. The UPS would immediately shut down reporting overload at 300W or higher. At a load of 250W the UPS would wait for 3-4 seconds and then shut down, too. Thus, this power supply is practically incompatible with UPSes (save for online models).

Output Voltage Stability

The Tagan is perfect is this test: the +12V voltage deflects no more than 1%. The +5V and +3.3V voltages deflect no more than 2%.

Output Voltage Ripple

The additional capacitors did not save the PSU from conspicuous spikes of voltage at the moments of the switching of the inverter’s transistors. However, the voltage ripple is not higher than the permissible limit at full load even though is close to that limit on the +5V and +3.3V rails.

Noisiness

The PSU is cooled by a 135x135x26mm fan whose real manufacturer can be identified from the model name. It is Globe Fan.

The fan’s speed is about 1000rpm until a load of 500W. Then the fan begins to accelerate up to 2000rpm. Overall, the PSU is average in terms of noisiness.

Efficiency and Power Factor

The efficiency is not recording-breaking but high: up to 87% at the maximum.

Summary

The Tagan BZ Series TG1100-U88 does not stand out among its numerous opponents, but may be interesting to people who like various kinds of highlighting. The indication of connected cables is implemented very beautifully in this PSU. The shortcoming of this model is its almost complete incompatibility with UPSes.

Tuniq Ensemble PSU-ENS-1200W (1200W)

Tuniq is another debutante in our PSU reviews.

Tuniq’s product comes in a box that can be easily carried in a plastic bag, but not handy otherwise: it is very large, flat and handle-less.

Exterior Design

The exterior design resembles the Chieftec CFT-1200G-DF which I reviewed recently. The similarity goes from the overall component layout to the sticker informing you that the fan is going to rotate for a while after the PSU shuts down.

The Ensemble is equipped with fixed cables. Its cables go out of the two holes in the back panel, but this can hardly affect the ease of assembly.

We’ve got the following cables here:

The connectors are rather scanty for a 1200W power supply. Without adapters you can only attach two top-end graphics cards and some six SATA drives. If that’s enough for your configuration, you can hardly want a 1200W PSU. And if that’s not enough, most of alternative products offer more connectors (three pairs for graphics cards and 8 to 12 SATA plugs, as a rule). Besides, the Ensemble’s cables are not long.

Interior Design

The internals confirm my supposition that this PSU is a kinsman to the Chieftec CFT-1200G-DF as it is made by Sirtec and is no different from Chieftec’s model in interior design.

The drawback of the component layout is that the input filter resides at the vent grid. The filter does not need much cooling but its chokes will hinder the air flow. Is it the reason why the developer had to install a second, 80mm, cooling fan?

Specifications

The PSU has typical specs for its class. There is nothing that might catch your eye here. The combined maximum load on the +12V rail is exactly equal to the load capacities of the four “virtual” output lines. It means that each line must be loaded to its full for the PSU to deliver the promised 1080W via its +12V rail. In most other PSUs the sum of the load capacities of the individual lines is higher than the total load capacity, which allows to distribute the load among the lines in a more flexible way.

UPS Compatibility

The PSU is practically incompatible with UPSes. Switching to the batteries makes the UPS shut down reporting overload even a load of 300W. It is only online UPSes, which do not have to switch to batteries at all, that can be used with such power supplies.

Output Voltage Stability

The PSU boasts exceptional stability of the output voltages, none of which goes out of the prescribed range at any load. The only downside is that it would shut down if the load was suddenly dropped from maximum to 10W or lower on the +12V rail. Anyway, I guess that a computer configuration that calls for a 1200W power supply will surely have an idle power consumption of over 10W despite all the newfangled power-saving technologies.

Output Voltage Ripple

The high-frequency ripple is within the acceptable range at full load. The shape of the ripple is smooth, without any spikes.

Besides, there is low-frequency ripple (at the double frequency of the mains, i.e. 100Hz) on the +12V rail. The sum of the high- and low-frequency pulsations is within the acceptable limits, too. But the very existence of the low-frequency component is not good.

Noisiness

The PSU is cooled by two fans, both manufactured by Globe Fan. The main fan measures 135x135x25 millimeters.

The second fan, measuring 80x80x15 millimeters, features cavities in the blades typical of some Globe Fan models. The developer says these cavities are designed to improve aerodynamic and noise characteristics of the fan.

Alas, it is the 80mm fan that was the main problem. It produced a soft but distinct noise even at minimum loads.

The fan speed management is designed in a queer way. The fans both speed up at a load of 750W. As a result, the PSU is somewhat worse than average in terms of noisiness until that load (mostly due to the 80mm fan because the 135mm fan is rotating rather slowly and is almost silent) but becomes noisy after it.

Efficiency and Power Factor

The PSU’s efficiency is not record-breaking, but good. It is almost 89% at the maximum and 81.5% at full load.

Standby Source

The standby source’s voltage is rather high at zero load (5.2V while the allowable maximum is 5.25V) but bottoms out to only 4.91V at full 6 amperes, which is much higher than the allowable minimum.

Summary

Although the Tuniq Ensemble PSU-ENS-1200W is not a bad power supply, it is inferior to most of its opponents. The Ensemble is bulky, has too few cables, is incompatible with UPSes, and is cooled with two fans, the smaller of which would produce a distinct noise even at low loads. Finally, its habit of shutting down when the load on the +12V rail is suddenly dropped to below 10W may be a problem for configurations with especially effective power-saving technologies.

Zalman ZM1000-HP (1000W)

The last product in this review comes from Zalman and its distinguishing feature is the use of heat pipes. As far as I know, this is the only PSU series to be equipped with such cooling technology. Some time ago I reviewed the ZM850-HP and was pleased with it. Now, let’s take a look at the higher-wattage model.

Exterior Design

The PSU is large but, unlike the Tuniq Ensemble, has only one cooling fan. The free area of the front panel is perforated for free flow of air.

The ZM1000-HP is a modular power supply. There are eight connectors for detachable cables at its back panel. The connectors are Molex Mini-Fit Jr., the same as are used in most other modular PSUs.

There is a Standby Noise Suppressor switch next to the connectors. When turned on, it loads the output of the standby source with a 20Ohm resistor. Otherwise, the standby source might hiss unpleasantly when idle. The Noise Suppressor is off by default in order to reduce the PSU’s idle power draw by about 1.5W (that’s a negligible amount, but the manufacturers are struggling to cut power consumption as much as possible nowadays). If you connect the PSU to your computer and hear no hiss, you don’t have to turn the Suppressor on (you can connect the PSU to the mains without connecting it to the mainboard for the comparison’s sake: the standby source load is zero then and my sample would produce a distinct hiss which vanished when I turned the Suppressor switch on).

The PSU is equipped with the following cables and connectors:

Included with the PSU are:

The only problem I can see here is that the cables are rather short. In a now-fashionable system case with cables hidden behind the mainboard and a bottom position of the PSU, the 50-centimeter CPU power cable just won’t reach to the mainboard. Besides, the PSU has only two pairs of connectors for graphics cards whereas most other PSUs offer three pairs. Of course, few users install three top-end graphics cards into their systems, but when you buy a 1000W PSU, you want to get everything possible with it.

Interior Design

It is hard but possible to identify this PSU as an Enhance product. Instead of Enhance’s massive and ribbed T-shaped heatsinks for cooling transistors and diodes, there are heat pipes secured with screws to heatsinks that have no ribbing at all. The pipes have thermal grease at the places of contact.

At the other end of the pipes there are heatsinks consisting of thin aluminum plates. The air flow from the PSU should go through these heatsinks and ensure better cooling than with ordinary heatsinks. I doubt the efficiency of this solution, though. Such heatsinks produce additional aerodynamic resistance and the air will bypass them rather than go through. We’ll discuss the cooling efficiency shortly, though.

Teapo capacitors are installed at the PSU’s output.

Additional high-frequency filters are fastened on the bunches of cables that go out of the PSU. Each filter consists of two halves of a ferrite tube in a plastic casing. Sometimes they begin to produce an irritating hiss when the load changes. If you have this problem, you can solve it by dismantling the PSU and removing the filters from the cables (you can unlock them with a thin-tipped screwdriver or knife). This will have no effect on the stability of the PSU. You can also try to fill the filter with epoxide resin to make it monolithic.

Specifications

Having a total output power of 1000W, the PSU can yield up to 960W via its +12V rail divided into six “virtual” output lines with max currents of 18A or 28A. As the table on the label shows, the more powerful lines refer to the fixed graphics card cables (with 6+2-pin connectors), which is reasonable. It is graphics cards that are the most voracious consumers in modern PCs. It should be noted that this load capacity (over 300W!) allows to place two power connectors on each cable, so the PSU might have three rather than two pairs of connectors.

UPS Compatibility

Together with an APC SmartUPS SC 620 this power supply worked at loads up to 400W when powered by the mains and up to 300W when powered by the batteries (if the load was higher than 300W, the UPS would shut down instantly). Thus, a UPS with sinusoidal output voltage and a reserve of wattage is recommended for the ZM1000-HP.

Output Voltage Stability

The PSU delivers very stable voltages: they only deflect more than 3% from the nominal values under extremely high loads (the allowable deflection being 5%).

Output Voltage Ripple

The output voltage ripple is much lower than the permissible limit at full load. Even the individual short spikes don’t spoil the overall picture.

Noisiness

The PSU is cooled by a 140x140x25mm fan that is marked as Zalman’s product. I guess the fan is actually made by some other firm, but I can’t identify it.

The fan is rotating at only 720-730rpm at loads up to 800W, making the one of the quietest PSUs in this review. It is second only to the Enermax Revolution 85+ whose fan is working at an even lower speed under low loads. On the other hand, the Zalman heats up a lot: the temperature of the air increases by 20 degrees in it.

The measurements might have been affected by the specific position of the heatsinks. I measure the air temperature at one spot, so the result may be higher if a hot stream of air hits that very spot. But there is no alternative as measuring the temperature at multiple spots would take much more time. Measuring the temperature of heatsinks as some other test labs do is even less accurate because the result depends on the particular spot and how hard the thermocouple is pressed to the heatsink. Besides, such measurements must be performed with the PSU’s cover on, which makes it hard to place the thermocouple and control how well it fits.

Efficiency and Power Factor

The PSU is 88% efficient at the maximum and over 83% efficient at full load. That’s a good result.

Standby Source

The ZM1000-HP’s standby source is rated for a rather low current of 3.5A and copes with its job well.

Summary

The Zalman ZM1000-HP is an interesting product. I don’t know how much the heat pipes contribute to it, but it is indeed one of the two quietest PSUs in this review. Unfortunately, the overall impression is somewhat spoiled by minor drawbacks. First, I guess a 1000W power supply should have more and longer cables. Second, the ferrite filters on the output cables begin to hiss under some loads in some samples of the PSU. Well, if you don’t run three graphics cards but want a quiet and high-wattage PSU, the ZM1000-HP will be a good choice, especially if you are not afraid of opening it up and removing the filters.

Conclusion

When I began this test session I did not expect to find any really bad samples of PSUs. There are generally no quality-related problems with 1000W and higher products as yet. Indeed, all of the 14 models I have discussed comply with their specs and show stable and reliable operation. However, there are products that can be specifically singled out as leaders.

First of all, it is the Enermax Revolution 85+ ERV1050EWT. Enermax has promised a power supply with best possible specs and seems to have delivered it. This is a quiet, high-wattage, stable PSU with a generous selection of connectors and excellent efficiency. Enermax is the best product in this review.

The Revolution series used to be the only one to boast 90% and higher efficiency. Now it has got an opponent in this respect. The OCZ Z series Z1000M is a high-quality, compact and rather quiet PSU that has an efficiency of 91.7%. It offers a good selection of cables, too, providing 12 connectors for SATA drives and three pairs of connectors for graphics cards.

The Zalman ZM1000-HP should be praised for quietness as its fan is hardly faster than 700rpm even at high loads! Unfortunately, this PSU is overall inferior to the Enermax. Being equally quiet, the Enermax offers more cables and connectors, has no potential problem with the hissing filters, and has better compatibility with UPSes.

The SilverStone Strider SST-ST1500 must be noted as the PSU with the highest wattage rating of 1500W. The lower-wattage models from SilverStone are not much different from their numerous opponents whereas the SST-ST1500 is by far superior to all other 1500W PSUs I have seen. It is based on a new platform from Enhance and features excellent stability and high efficiency. It does not have any specific requirements to load distribution and is also quiet. If you need so much power, take a look at the SilverStone Strider!

Users of system cases with a bottom position of the PSU may want to consider PSUs with long cables such as the Akasa PowerMax AK-P100FG and SilverStone Strider SST-ST1200 and SST-ST1500. Their CPU cable is over 70 centimeters long, so you can lay the cable neatly in any system case.

And finally, aesthetes may like the beautiful highlighting of the detachable cable connectors of the Kingwin Mach I ABT-1000MA1S and the Tagan BZ Series TG1100-U88. The former is also nicely quiet at work.

Summing up the results of our today’s test session we are proud to award Enermax Revolution 85+ ERV1050EWT (1050 W) power supply unit with our prestigious Editor’s Choice title as the best 1000 W+ power supply unit: