High-Capacity Power Supply Units Roundup: Eleven 800-850 W PSUs

This roundup discusses eleven power supply units from different manufacturers with capacities from 800 to 850 W. You will meet solutions from familiar makers as well as from the companies, which PSUs are featured in our article for the first time.

by Oleg Artamonov
06/11/2010 | 10:41 AM

This article is rather strictly limited to a narrow range of power supply wattage ratings: from 800 through 850 watts. But notwithstanding this restriction, we’ve got as many as 11 models from different brands. Some of the brands are known to everyone and others make their debut in our PSU tests.

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 that article for explanation.

You can also go to our Cases/PSU section to check out reviews of all 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 tested PSU can meet the requirements of a real-life PC.

Testing Participants

Antec TruePower Quattro TPQ-850

Although it is the Signature series that is officially positioned as the most prestigious one in Antec’s product line-up, the TruePower Quattro is superior in terms of wattage ratings. The topmost Signature series model is rated for 850 watts but that’s only the starting point for the Quattro series. So, I am going to discuss the junior model of the Antec Quattro series which has a wattage rating of 850 watts.

The PSU comes in a medium-sized box painted bright yellow. The wattage is printed on the box in large letters. The product name is in smaller print.

Exterior Design

One feature of this PSU catches the eye right away: it uses an 80mm fan for cooling. Of course, I have seen even higher-wattage models being cooled by 80mm fans but that’s not a popular solution. Such PSUs are generally very noisy.

On the other hand, an 80mm fan is not overall inferior to 120mm or 140mm ones. A large fan blows at the PSU from above (and the 90-degree turn of the air flow leads to higher aerodynamic resistance) and creates a dead zone with slow air flow at the back of the PSU case. The manufacturers try to avoid this by covering a part of the fan with a piece of celluloid film. As opposed to large fans, an 80mm one blows along the heatsinks and PCB and distributes the air uniformly inside. There is no turning of the air flow and no dead zone. However, small fans can pump less air rotating at the same speed, and there may still be small dead zones if some components get obscured by larger ones.

Cutting it short, both large and small fans have their highs and lows, and you are going to learn soon whether this cooling solution works well in the TruePower Quattro.

The PSU is semi-modular, meaning that some of its cables are detachable. There are five connectors for them. Despite the different color, these connectors are identical electrically and mechanically – you can plug any cable into any connector. They only differ in the +12V lines attached to them.

The small number of connectors must be due to the 80mm fan. The developer had to make the back panel as “transparent” for the air flow as possible.

Interior Design

It is hard to see anything inside the PSU behind the huge heatsinks. One can note, however, that the TruePower Quattro features active PFC and dedicated voltage regulation.

KY series electrolytic capacitors from United Chemi-Con are used at the PSU’s output.

Specifications

The PSU is rated for an output power up to 850 watts and, as the manufacturer notes, can yield it all at an ambient temperature up to 50°C just as required by the ATX12V standard. The +12V rail is split up into four “virtual” 25A lines and has a combined max load of 768 W (64 A).

Cables and Connectors

The PSU is equipped with the following cables and connectors:

Despite the different color and labels, the connectors for detachable cables are identical both mechanically and electrically. They only have different +12V lines attached to them.

Included with the PSU are:

Take note that the detachable graphics card cables are connected to 6-pin PSU connectors in which two pins (+5 and +3.3 volts) are not necessary for graphics cards. The manufacturer’s solution to equip these cables with 6+2-pin connectors is dubious. I wouldn’t recommend using them for top-end graphics cards.

There are more cables included with the PSU than there are connectors in it, so you can choose what cables are necessary for your particular PC configuration. You won’t have to mess up with redundant cables (take note that there are peripheral power cables with either two or three connectors) and you won’t feel a lack of connectors with some very specific configuration (e.g. if you’ve got a lot of PATA drives). This is preferable to having fewer cables with more connectors on each.

I want to remind you that if the two fixed graphics card cables are enough for you, you can connect all six HDD power cables to the PSU connectors, which are all identical.

UPS Compatibility

Working with my APC SmartUPS SC 620 uninterruptible power supply, the TruePower Quattro TPQ-850 was stable at loads up to 375 W when powered by the mains and up to 340 W when powered by the batteries. They had no problems switching to the UPS’s batteries.

Output Voltage Stability

The three main voltages deflect no more than 3% from their nominal values within the permissible load range. There is nothing to criticize this PSU for.

Output Voltage Ripple

Everything is all right with the +5V and +12V rails but the voltage on the +3.3V rail shows strange waves with a frequency of about 20 kHz. I say strange because it is unclear where this frequency originates from. PSUs usually have high-frequency pulsation at the frequency of the PWM regulator, i.e. over 100 kHz in modern models. Sometimes they also have low-frequency pulsation at a double frequency of the power mains (100 Hz in my region). Anyway, this pulsation is still within the permissible 50 millivolts.

Noise

This power supply is cooled by an 80x80x25mm fan from Adda (AD0812UB-A70GL).

The fan starts out at a speed of about 1900 RPM and keeps it nearly constant at loads up to 500 watts. Alas, the air produces a distinct sound passing through the densely packed innards of the PSU even at minimum loads. Therefore, the TruePower Quattro is only average in terms of noisiness. Its noise is neither loud nor irritating but may be noticeable in a home environment.

Efficiency and Power Factor

The PSU boasts a high but not record-breaking efficiency: higher than 88% at the peak and well above 80% at loads higher than 100 watts.

Standby Source

The standby source copes with its job just fine. Its voltage is never lower than 5 volts even at the highest permissible load.

Summary

Although the Antec TruePower Quattro TPQ-850 is not exceptional as today’s high-wattage PSUs go, it is quite a decent product in itself. It has perfectly stable voltages, high efficiency and a good selection of cables. On the downside are the fan which might be quieter and the PSU connectors for graphics card cables which are not designed for high loads.

The special feature of this PSU – its 80mm cooling fan – makes it an excellent choice for owners of system cases that do not allow to install a PSU with a 120mm fan, like many entry-level servers. Compared with most other high-wattage PSUs with 80mm fans, e.g. PSUs produced under the PC Power&Cooling brand, the TPQ-850 is preferable due to its rather quiet fan, small dimensions and modular design.

Cooler Master RealPower M850 (RS-850-ESBA)

The next model to be discussed is more typical in terms of its design. It is cooled by a 135mm fan as has become de facto standard for medium and high-wattage power supplies.

I want to note that Cooler Master offers two 850-watt RealPower series models. One has fixed cables and another has modular cables. I will be talking about the modular version.

The PSU comes in a large white box with a carry handle.

Exterior Design

The PSU looks ordinary enough. The only interesting thing in its appearance is that its front panel is “transparent” for the air. It is all perforated save for the zone with a mains connector and an On/Off indicator.

There are six connectors for peripheral power cables and four for graphics cards, which is more than the above-discussed Antec TruePower Quattro offers. You cannot confuse connectors as they are shaped differently.

Interior Design

Removing the cover, I could instantly tell the real manufacturer of this power supply. It is Enhance. This PSU has two power transformers working in parallel, an active PFC device, and dedicated voltage regulation based on magnetic amplifiers. As is typical of Enhance products, the quality of assembly is very high.

There are Teapo capacitors at the PSU’s output. Teapo is a respectable brand.

Specifications

This PSU has as many as six “virtual” +12V lines rated for a max current of 28 A (the graphics card lines) or 18 A (the rest of the lines). This abundance of power lines allows distributing the load without worrying that one particular line might overload the whole PSU (such an unpleasant thing occurs when the overload protection of a PSU with virtual output lines is triggered by an exceedingly high current on any particular line whereas the total PSU load is yet far from maximum). Well, PSUs that have no splitting of the +12V rail into multiple lines have no such problem at all.

Cables and Connectors

The PSU is equipped with the following cables and connectors:

Included with the PSU are:

This selection of cables and connectors looks good, yet not perfect to my taste. First, the fixed 4-pin CPU connector on a separate cable won’t be needed by a majority of users because they will instead use the fixed 8-pin one. Mainboards with both power connectors are rather rare (server boards, mostly). Second, I would prefer four SATA power cables, even with fewer connectors on each, to the included two because one cable usually goes to the optical drive and does not reach to the HDDs.

UPS Compatibility

Working with my APC SmartUPS SC 620, this power supply was stable at loads up to 366 W when powered by the mains and up to 335 W when powered by the batteries. They had no problems switching to the UPS’s batteries.

Output Voltage Stability

 

The PSU was not stable when the load on the +3.3V rail was low (below 1 A). Otherwise, there were no problems: every voltage deflects no more than 3% from its nominal value.

Output Voltage Ripple

 

The output voltage ripple is within the norm on every of the three main power rails at full load.

Noise

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

 

The fan’s speed is constant and below 900 RPM at loads up to 500 watts. It begins to rise at higher loads, reaching a maximum of 1450 RPM. The PSU would be very quiet if it were not for the rumbling sound the fan of my sample produced even at low speeds. However, I have seen a lot of PSUs with YLTC fans that had no such problems (including PSUs manufactured by Enhance), so I have no doubts that this is a problem of the specific sample of the fan.

Efficiency and Power Factor

 

The PSU is over 80% efficient, reaching a maximum of 88%. It is 82.5% efficient at full load.

Standby Source

 

The standby source is rated for a current up to 3.5 A. Its voltage sags to 4.9 V under full load, the permissible minimum being 4.75 V.

Summary

I have seen a number of high-quality power supplies from Cooler Master and the RealPower M850 can now be counted among them. It is a modular PSU with a handy selection of cables, good electrical parameters and low fan speed. I have to confess that my sample of the PSU had a defective fan, but practice suggests that no maker can guarantee the lack of such defects.

Corsair HX850W (CMPSU-850HX)

The HX series of Corsair power supplies is supposed to be a top series although often does not differ much from the mainstream TX. Today, I will check out the difference by testing an expensive HX850W model first and then comparing it with a TX850W.

The PSU comes in a medium-sized box. Corsair has a particular color for each series: blue for the HX, yellow for the TX and green for the inexpensive VX series.

Exterior Design

The same blue color is used in the design of the PSU itself. Every label is blue. Otherwise, it is an ordinary box painted a matte black paint.

Like most PSUs of its class, the HX850W is modular. It has six connectors for peripheral power cables and four for graphics cards. The connectors differ from each other in their color and number of pins, so you can hardly confuse them.

Interior Design

The Corsair HX series is associated with Seasonic by many users. It is by Seasonic that the expensive but popular HX520W and HX620W were manufactured. However, the HX850W (and the higher-wattage HX1000W) is produced by another renowned maker, Channel Well Technology (CWT).

This model has nothing in common with the HX1000W which had a very queer design (in fact, it consisted of two 500-watt power supplies in a single housing). It is not the well-known PSH platform Channel Well has been using for years to produce PSUs for many brands, either.

The main distinguishing feature of the new platform is the use of two DC-DC converters to obtain +3.3 and +5 V. In other words, the main part of the power supply generates +12 V whereas the lower voltages are produced out of +12 V by means of full-featured converters (as opposed to PSUs with regulators based on magnetic amplifiers which are not truly independent and can only work when driven by a switching voltage). You can see the two DC-DC cards in the photo above.

This design ensures good voltage stability (I will check this out shortly) as well as higher component density (the upright converter cards take rather little space). It also makes the main power transformer simpler as the latter now has only one secondary winding for +12 V and no 5V tap. Until recently, such converters have been rare due to high cost, but seem to be ready now to become a de facto standard for mainstream and top-end PSUs, replacing magnetic regulators with their bulky chokes.

The PSU has both solid-state capacitors (in the DC-DC converters) and electrolytic ones (KZE series from United Chemi-Con) at the output.

Specifications

This PSU has a solid +12V power rail without any “virtual” output lines. The max load on that rail is a mere 10 watts lower than the total allowable load for this PSU. The HX850 is ideal in this respect.

Cables and Connectors

The PSU is equipped with the following cables and connectors:

Included with the PSU are:

There are as many as six graphics card cables here! The PSU can power up to three top-end graphics cards with 8-pin power connectors without any adapters. Most 850W units offer but four connectors, so if you are going to assemble a 3-way GPU configuration, you may consider the Corsair HX850W as an option.

UPS Compatibility

Working with my APC SmartUPS SC 620, this power supply was stable at loads up to 372 watts when powered by the mains and up to 350 watts when powered by the batteries. They had no problems switching to the UPS’s batteries.

Output Voltage Stability

 

 

The PSU keeps its output voltages very stable: the +12V voltage barely goes beyond 1% deflection. The +5V is within 2% and the +3.3V voltage is within 3% from the nominal value.

Output Voltage Ripple

 

 

High-frequency voltage ripple can hardly be observed at the output of the HX850W even at full load. The oscillogram shows but small spikes of voltage which are far below the permissible limits.

Noise

This PSU is cooled by a 140x140x25mm fan from Yate Loon. Its impeller is partially covered by an intricately shaped plate that helps avoid a dead zone at the back of the PSU case in which the speed of the airflow would be too low to cool the components effectively.

The fan starts out at 1000 RPM and keeps this speed until a load of 600 watts. At full load the fan is barely faster than 1350 RPM.

The PSU cannot be called silent due to the rather high initial speed of the fan, but under high loads it proves to be quieter than most opponents which accelerate their fans in a more aggressive way. Thus, the noisiness of the HX850W is going to depend on how advanced and hot your particular configuration is.

Efficiency and Power Factor

 

Not long ago I used to be very glad to see PSUs with an efficiency of 80% and higher. But now we’ve got models that are over 90% efficient! The efficiency lowers only to 89% at full load, which is an excellent result.

Standby Source

 

The output voltage of the standby source lowers by a mere 0.1 V as the load changes from zero to maximum. It remains much higher than the permissible bottom limit.

Summary

The Corsair HX850W has no serious drawbacks. Its voltages are stable and there is low output voltage ripple. It is highly efficient and offers a lot of connectors with which you can connect three graphics cards and about ten hard disk drives using no adapters. The only thing I can find fault with is that the fan is never slower than 1000 RPM. It means you should not buy the HX850W for a mainstream PC configuration, hoping that it will be silent. On the other hand, this PSU is going to be an excellent choice for high-performance computers.

Corsair TX850W (CMPSU-850TX)

This is another model from Corsair. It has the same wattage rating of 850 watts but hails from the more affordable TX series.

The packaging of this series is yellow.

Exterior Design

Besides the color of the labels, this model is shorter than the HX850W and, which is more important, lacks detachable cables.

Interior Design

Despite Corsair’s having removed all markings from the chokes and transformers, I can easily tell the PSH platform from Channel Well Technology here as I have seen it in dozens of products selling under different brands. It seems to be the most popular platform for branded PSUs in the world and has been selling successfully for years, undergoing but minor revisions. Like the HX850W, this PSU has dedicated voltage regulation but the latter is based on magnetic amplifiers with chokes rather than on DC-DC converters.

KZE series electrolytic capacitors from United Chemi-Con are installed at the PSU’s output. A few solid-state capacitors have been thrown in as well. 

Specifications

This PSU can yield nearly all of its output power – 840 out of 850 watts – via the +12V rail which is not split into multiple output lines. The PSU is just as good as its more expensive HX series cousin in terms of load capacity. It even has more robust +5 and +3.3V rails although this is no advantage. Today’s computers just don’t load those rails much.

Cables and Connectors

The PSU is equipped with the following cables and connectors:

The TX850W is inferior to the HX850W in this respect, having fewer cables for both graphics cards and HDDs. Anyway, it is going to be able to power most top-end gaming configurations without any adapters, too.

UPS Compatibility

Working with my APC SmartUPS SC 620, this power supply was stable at loads up to 365 watts when powered by the mains and up to 330 watts when powered by the batteries. They had no problems switching to the UPS’s batteries.

Output Voltage Stability

 

The +12V voltage is ideal, deflecting less than 1%. The other two voltages deflect less than 3%, which is a good result, too.

Output Voltage Ripple

 

High-frequency pulsation can be observed on each of the three main power rails but it is far below the permissible limits.

Noise

The PSU is cooled by a 140x140x25mm fan manufactured by Onghua. I guess it’s the first time I ever hear this name. I’m not inclined to trust such obscure brands but the fan did not produce any foreign noises in my sample of the PSU. The impeller is half covered with a piece of translucent plastic film.

 

The fan is rotating at about 900 RPM until a load of 400 watts. Then it rapidly accelerates, reaching a peak speed of 2000 RPM. The TX850W is going to be a little quieter than the HX850W under low loads, but the latter will be much better under medium and high loads.

Efficiency and Power Factor

 

Although not new, the PSH platform can still deliver good results: the efficiency is 87% at the peak and easily remains above 80% in the load range of 100 watts to full load.

Standby Source

 

The standby voltage is set somewhat higher than necessary by default (within the permissible limits, though), which helps it keep above 5 volts at full load.

Summary

While the Corsair HX850W is a newest model representing a newest platform, the TX850W is yet another reincarnation of the well-known PSH platform from Channel Well. However, this PSU delivers good electrical parameters and is overall a good choice for a top-end gaming computer.

You may only want to prefer the more expensive HX series model if you need its higher efficiency and quieter operation at high loads. Besides, the HX model has more connectors and modular cables.

Enermax MODU87+ (EMG800EWT)

Enermax once gathered my praises for its MODU82+ and PRO82+ series products (the number in the name denotes the bottom efficiency in the typical load range).

Today, I am going to discuss the further development of the MODU series, the MODU87+ power supply. As you may guess from its name, it is expected to be over 87% efficient!

The PSU comes in a medium-sized box with a huge “80+Plus Gold” label forming the background. This is the top level of the 80+Plus certification this PSU is supposed to comply with.

Exterior Design

The prestigious status of the product is expressed in its appearance, especially in the shining gold impeller of the fan.

The MODU87+ is a modular power supply. It has five connectors for peripheral power cables and three combined connectors for graphics card cables. The latter are a special pride of Enermax since the 12-pin connector has a higher load capacity and can be used to connect cables with two end connectors.

Enermax also offers the PRO87+ series which has the same parameters but lacks detachable cables. If you don’t need the modular design, you may want to prefer the PRO87+ series because it is somewhat cheaper.

A few minor but interesting details can be spotted in the appearance of this power supply.

The metal around the fan is shaped in such a way as to reduce the gap between the fan and the case. Enermax engineers argue that this helps lower the noise by 1-2 dB. Interestingly, I have seen this solution in Enermax power supplies before, but implemented in a different way. And I have also seen this exact shaping of the case in PSUs from OCZ and Chieftec! Is it a coincidence or deliberate borrowing? Or could it be the result of one manufacturer working for multiple clients?

I was at first puzzled by the invitation to glue the Enermax sticker to the PSU with my own hands (the sticker is included with the PSU). Why didn’t they do that at the factory? The answer is simple: you can glue the sticker depending on how the PSU is positioned in your system case so that the name of the manufacturer is not upside down.

This solution still does not account for system cases with a vertical position of the PSU (such as some large HTPCs), but I guess that most users don’t care at all what labels there are at the back of their computer.

Take note of the two grooves in the case below the mains connector. You are supposed to insert this wire bracket into them:

The bracket serves as a cable holder and prevents the mains cable from unplugging if someone just pulls at it. You may appreciate this feature if you’ve got a restless dog or a small child in your home.

Interior Design

The MODU87+ looks like an ordinary modern PSU with active PFC and dedicated voltage regulation based on DC-DC converters. However, the manufacturer lists the so-called resonance topology of the main transformer among its features. You can identify it by the extra choke which is missing in other PSUs.

This topology does not bring anything interesting to end-users, though. A resonance transformer is a control circuit that minimizes switching loss by switching transistors at near-zero levels of voltage and current (such PSUs are often referred to as ZVS/ZCS or Zero Voltage Switching and Zero Current Switching). Resonance-topology power supplies are produced by Enermax and other firms already, e.g. by FSP (you can find them at shop selling under the brands of Silverstone, Zalman, etc).

Compared to an ordinary transformer, a resonance transformer has an extra choke and capacitor with such characteristics that the resonant frequency of this LC circuit matched the time period during which the inverter's transistors are open. Thus, in an ordinary transformer, the current grows up linearly when the transistors are open and reaches its maximum at the moment of switching off, but in a resonance transformer the current is sinusoidal, reaching its maximum in the middle of the cycle and lowering to zero by the time the transistors must close. The document Power Semiconductor Applications: Switched Mode Power Supplies by NXP Semiconductors explains this in detail and in comprehensible language (for those who know the basics of switching power supplies, of course) on page 219 (117).

By the way, as the period during which the transistors are open must not change in resonance mode, resonance transformers are controlled by means of pulse frequency modulation (PFM) rather than pulse width modulation (PWM),

The lower loss on the transistors means higher efficiency, lower heat dissipation and lower EMI from the PSU. However, it does not affect the output parameters of the PSU. So, if you don't care much about how efficient your PSU is, models with resonance transformer won’t have any special appeal to you.

As noted above, the PSU produces +5V and +3.3V voltages by means of two full-featured DC-DC converters but, unlike in the Revolution series products, these converters are mounted on the main PCB rather than on the card with output connectors. Two narrow cards with capacitors can be seen nearby: this solution helps achieve the required capacitance and save space. Both electrolytic (KZE series from United Chemi-Con) and solid-state capacitors are used here.

And finally, here is one more peculiarity in the assembly of this PSU. High-load conductors of a PCB are usually tin-plated in order to reduce loss (this is often done in a grid-like pattern as can be seen in the top left of the photo). When solder alone is not enough, a piece of naked copper wire is laid along the conductor and covered with solder as well. The engineers went further with the MODU87+: there are whole copper plates soldered to and shaped like the conductors.

Specifications

The PSU is rated for an output power of 800 watts and can yield 792 watts via its +12V power rail which is split into four “virtual” output lines. The load capacity of the +5V and +3.3V rails is rather low, but modern computers hardly ever need more than 50 watts out of them, so the available 120 watts should be enough for any real-life situation.

Cables and Connectors

The PSU is equipped with the following cables and connectors:

Included with the PSU are:

This selection of connectors should be all right for most configurations but I guess that most users won’t need two separate CPU power cables. One of them might have been made detachable, especially as one of the three connectors for graphics card cables is going to be unoccupied if you use the included cables only.

UPS Compatibility

Working with my APC SmartUPS SC 620, this power supply was stable at loads up to 390 watts when powered by the mains and up to 355 watts when powered by the batteries. They had no problems switching to the UPS’s batteries.

Output Voltage Stability

 

The PSU delivers a stable +12V voltage which deflects no more than 2% from the nominal value, but the +5V and +3.3V voltages get close to the permissible limits: the former under maximum load and the latter under minimum load. On the other hand, the voltages are all within the required limits and do not deflect much under typical loads.

Output Voltage Ripple

 

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

Noise

Enhance used to be fond of special fans in its power supplies such as fans with originally shaped blades or with 4-pin connection. Somewhat unexpectedly, the MODU87+ has a 140mm fan with the exclusive Twister Bearing but without any remarkable external traits.

Well, if you take a closer look, you will find the fan to be not so ordinary after all. It is connected with 3 wires, but that’s neither a standard 3-pin fan with tachometer output and nor a PWM-controlled fan.

The bottom limit for a fan’s voltage is determined by its control chip. The latter cannot work if the voltage is too low and the fan halts then. In PWM-controlled fans the chip is powered by 12 V while its speed is regulated by means of pulse width modulation at a frequency of 25 kHz via a separate wire.

Enermax came up with a different solution. On one hand, its fans are not PWM-controlled. And on the other hand, they have a broader speed range than classic 3-pin fans. The fan gets two supply voltages: the controller chip is powered by +12 volts whereas the voltage of the motor varies.

The table above lists conventional methods of connecting fans as compared with the Enermax fan. Easy to see, the main consequence of this discrepancy is that it is hard to find a replacement fan if the native one fails. Perhaps you can take an ordinary 3-pin fan and connect it to the “ground” and the second power pin (the one with varying voltage), leaving the tachometer output unconnected. And don’t forget to check out that the fan will be able to rotate at the bottom voltage.

When it comes to the EMG800EWT, its fan does not slow down to some record-breaking levels. Its bottom speed is 700 RPM. The PSU is very quiet, nearly silent, and remains quite comfortable acoustically even at full load when the fan accelerates to 1200 RPM.

The single downside I could spot was a weak but distinct electric noise I could hear from the PSU at zero load. On the other hand, there are no computers that consume 0 watts.

Efficiency and Power Factor

As promised by the manufacturer, the PSU’s efficiency is as high as 93% at the peak and only falls below 88% at very low loads when the PSU’s own power consumption in idle mode becomes important.

Standby Source

When the load was increased to 1 ampere, the standby voltage sagged alarmingly. However, it eventually stabilized at 4.9 volts, which is perfectly normal.

Summary

Enermax enjoys a good reputation and has not failed today, either. The MODU87+ can be recommended as a high-wattage, modern, stable and quiet power supply for gaming computers. It has only one downside. Its nonstandard fan may be hard to replace if you want to do that for some reason.

I want to emphasize the fact that the EMG800EWT is up to 93% efficient, which is the all-time record for power supplies ever tested in our labs. I have no doubt that the other brands will soon roll out their own 80+Plus Gold products, too.

Enhance EPS-1280GA

The next product to be discussed is the 800-watt EPS-1280GA from Enhance. It comes in original packaging.

I’m not sure what the designer’s concept is here, but the black box padded with black cloth on the inside provokes thoughts about the futility of life in me. Hopefully, the power supply will be much livelier in my tests…

Exterior Design

The PSU has a small and completely black case without any remarkable features. The front panel is perforated as heavily as possible. The On/Off switch has been sacrificed for the sake of airflows, too. The PSU is equipped with fixed cables.

Interior Design

It is the characteristic shape of the heatsinks that betrays an Enhance power supply. Well, we don’t have to guess the real manufacturer of the PSU here because this product sells under Enhance’s own brand.

The EPS-1280GA is designed in a conventional way without any newfangled ideas like a resonance inverter or DC-DC converters.

Teapo capacitors are installed at the PSU’s output.

Specifications

This model can yield up to 780 watts (65 amperes) out of its total 800 watts via the +12V power rail which is split into four “virtual” lines with different current limitations. The high-current lines are meant for graphics card cables, as usual.

Cables and Connectors

The PSU is equipped with the following cables and connectors:

This PSU is no better than the rest of the models covered in this review in terms of connectors or cable length, but not much worse, either. It has all power connectors necessary to build a modern gaming computer.

UPS Compatibility

Working with my APC SmartUPS SC 620, this power supply was stable at loads up to 350 watts when powered by the mains and up to 340 watts when powered by the batteries. They had no problems switching to the UPS’s batteries.

Output Voltage Stability

The PSU keeps the three main output voltages within a 3% range from their nominal level at any load. That’s good.

Output Voltage Ripple

Although the high-frequency pulsation of the output voltage can be easily observed, it is far lower than the permissible limits.

Noise

This power supply is cooled by a 120x120x25mm Adda fan with 2-pin connection.

Enhance power supplies usually produce a long and flat graph of the fan speed at low and medium loads but the EPS-1280GA is different. The fan accelerates steadily starting from 150 watts.

Since the initial speed is as low as 533 RPM, the PSU is quiet. It can hardly be heard at all at loads below 350 watts and its noise only becomes uncomfortable at loads of 600 watts and higher.

Efficiency and Power Factor

The EPS-1280GA boasts good efficiency of 89% at the peak, over 86% at full load, and over 80% at any loads above 50 watts. I’d even say that’s an excellent result!

Standby Source

Despite a high load capacity, the standby source yields a stable voltage. There is only about 0.1 volts between the maximum and minimum.

Summary

I have not mentioned any innovative technologies when talking about the Enhance EPS-1280GA power supply. It has a plain exterior and standard functionality, yet leaves a highly positive impression. It is a quiet and stable high-wattage PSU that can easily cope with a serious gaming computer. It seems to be the best choice for users who just need a good PSU and don’t want to pay extra for shining LEDs or promo posters.

Huntkey HK901-11PEP

We have never tested Huntkey products in our labs and there is one critical remark right from the start: calling an 800-watt model “HK901-11PEP” does not sound good to me.

Exterior Design

We’ve got a standard black power supply here. The chrome-plated fan grid is the only remarkable feature. The PSU is rather compact, measuring exactly to accommodate the 14cm fan.

Like most other PSUs in this review, the HK901 is modular. There are eight connectors for cables on its back panel. The connectors differ in color and keys, but you should not blindly rely on the latter as they allow pushing an HDD power cable into a 6-pin connector for a graphics card cable.

Interior Design

There are two things I can note about this design: the component density is very high and there are very small heatsinks on the power semiconductor components. The heatsinks are nothing more than thick but absolutely finless bars of aluminum. The PSU needs to be highly efficient or have a fast fan in order to cool such heatsinks, considering the high component density. You’ll learn shortly which way the developer went with this product.

Otherwise, the PSU is quite a standard device and does not even try to match the products from Enermax and Seasonic in terms of innovations per cubic centimeter. Like all other models in this review, it features dedicated voltage regulation but it is based on chokes (a magnetic amplifier design) rather than on DC-DC converters. 

Specifications

Looking at the label, you can once again note the discrepancy between the numbers in the PSU name (HK901) and specified output power (800 watts). You can also take note of the high load capacity and “classic” splitting of the +12V power rail into 18-ampere lines. In most power supplies of similar wattage that retain this split-rail design, the graphics card power lines have a max current of 22-25 amperes, which ensures more flexibility in connecting the load. To remind you, overloading one “virtual” power line triggers the PSU’s protection and shuts the whole PSU down although the latter might still be a large reserve of output power.

Cables and Connectors

This PSU is equipped with the following cables and connectors:

Included with the PSU are:

The color of the graphics card cables must be matched with the color of PSU connectors: the red ones are for 6-pin connectors and the blue ones are for 8-pin connectors. The four PSU connectors and six cables offer you more flexibility: you can power two top-end graphics cards or three mainstream graphics cards, for example.

I like the cable with three SATA and one PATA power connector. The latter is usually used in a modern computer for powering a fan or some indicator panel, etc. There is no point in using a separate PSU cable for that.

UPS Compatibility

Working with my APC SmartUPS SC 620, this power supply was stable at loads up to 355 watts when powered by the mains and up to 350 watts when powered by the batteries. They switched to the batteries normally and the UPS worked for half a minute but then reported overload and shut down. Thus, you need an UPS with a reserve of wattage (compared to the real power consumption of your computer rather than to the specified output power of the PSU) or with a sinusoid output voltage for the HK901-11PEP.

Output Voltage Stability

We can only see some red color in the diagram when the +5V voltage gets to its permissible limit under extremely high load, which can hardly occur in a real-life computer. And even that voltage did not violate the limit anyway.

Output Voltage Ripple

The three main voltages fit within the permissible limits in terms of high-frequency pulsation.

Noise

This PSU is cooled by a 140mm fan from Yate Loon. Despite the transparent impeller, the fan has no highlighting.

The fan keeps a constant speed of 900 RPM until a load of 450 watts. Then it begins to accelerate, reaching a maximum of 1600 RPM. So, the HK901-11PEP is a quiet power supply. It does not get very hot at work, which indicates high efficiency.

Efficiency and Power Factor

Indeed, the PSU is over 90% efficient at the peak and 87% efficient at full load. It is now clear how the developers managed to ensure proper cooling of this high-density PSU using modest heatsinks. The PSU just doesn’t generate too much heat!

Standby Source

The standby source copes with its job superbly. Its output voltage is never lower than 5 volts even under full load.

Summary

The Huntkey HK901-11PEP is good. It has a handy selection of cables and connectors. It is stable, efficient and quiet. Thus, it is going to be a good choice for a top-end gaming machine or a workstation. The downside is that it was not stable with my UPS that has a non-sinusoid output voltage. But considering that the pair switched to the batteries normally, I don’t expect any problems with UPSes that produce a sinusoid output voltage.

Kingwin Lazer LZ-850

Kingwin products have been tested in our labs just once before.

The PSU comes in a brightly painted box that can tell you a lot of technical details about its contents.

Exterior Design

Just another matte-black power supply. That’s the only thing I can tell about the Lazer LZ-850 until turning it on.

The PSU features a modular design with eight identical connectors on its back panel. The connectors are made from transparent plastic.

Although protective caps are not necessary for connectors separated by insulating plastic partitions (there is low chance of short-circuiting neighboring connectors), the Kingwin power supply has them: neat silicone caps.

The connectors are transparent for a purpose: they are highlighted by rather bright LEDs when cables are plugged into them. The PSU fan is highlighted as well. The connectors on the cables are made from transparent plastic, too.

The highlighting color can be changed to blue by means of a switch located near the mains connector (you can see it in one of the photos above; it is a small red lever). You can also turn the illumination off altogether.

Interior Design

There are no peculiarities deserving a particular interest in the electronics of this PSU. It is an ordinary modern model with active PFC, a single-step transformer and dedicated voltage regulation based on magnetic amplifiers. The rather large finned heatsinks are painted gold, but that’s just an aesthetic feature.

Pce-tur capacitors are installed at the PSU output.

Specifications

The 12V rail is split into five “virtual” lines, two of which are rated for a max current of 33 amperes and the other three, for 20 amperes. The combined load capacity of the +12V lines is but slightly lower than the PSU's total output power.

The standby source has a high load capacity, up to 5 amperes. I will check out shortly if it can really cope with such load.

Cables and Connectors

The PSU is equipped with the following power cables and connectors:

Included with the PSU are:

I can make the same comment as for the Enermax power supply. Few people need a second CPU power cable, so it might have been made detachable. Besides, at least one of the CPU power cables should be no shorter than 60-65 centimeters. Otherwise, it may prove too short to reach the connector in a system case where the PSU compartment is at the bottom and the mainboard is of a full-size form-factor (an extension cable would lower stability, especially in a system with a highly overclocked 4- or 6-core CPU that has high power requirements). This remark refers to other PSU makers, not only to Kingwin, though.

UPS Compatibility

Working with my APC SmartUPS SC 620, this power supply was stable at loads up to 350 watts when powered by the mains and up to 334 watts when powered by the batteries. They had no problems switching to the UPS’s batteries and the UPS was stable.

Output Voltage Stability

The +12V voltage is near ideal. The +5V and +3.3V are not that stable, but do not deflect more than 4%, anyway.

Output Voltage Ripple

The output voltage ripple is within the permissible limits except for occasional spikes which are not going to affect the stability of the PSU (especially as they are partially due to the somewhat inadequate reaction of my inexpensive digital oscilloscope to the high-frequency signal constituents).

Noise

The PSU is cooled by a 140mm fan from Globe Fan. It is an ordinary thing with a 2-pin connection. The abundance of cables you see in the photo is due to the two-color highlighting.

The speed of the fan does not change much until a load of 700 watts, being barely above 750 RPM. Then the fan begins to accelerate but does not reach 1000 RPM even at full load. The power supply is going to speed up its fan sooner in a computer with a top PSU compartment, being warmed up by the hot air from the CPU and graphics card, yet the LZ-850 can be considered a very quiet model anyway.

The noiselessness comes at the expense of temperature. Although cool under low loads, the PSU can heat the passing air up by 15°C and more when under high loads. This is yet another reason for choosing a system case with a bottom position of the PSU for a top-end PC configuration because this ensures better cooling for the PSU as well as for the rest of components.

Efficiency and Power Factor

The PSU is up to 87% efficient. Its efficiency at full load is 84%. This is a good, although not record-breaking, result.

Standby Source

Although the standby source is rated for a current of 5 amperes, its voltage drops below the permissible bottom limit (4.75 volts) as soon as 3.5 amperes. Most other PSUs, although limited to a max current of 3.5 amperes, deliver a voltage of 4.9 volts at that load. The LZ-850 is inferior to them in this respect.

Summary

The good news about the Kingwin LZ-850 is that it has a very quiet fan which is faster than 800 RPM at high loads only (such loads can occur but rarely even in a gaming computer with a couple of graphics cards). The downside is that, although the standby source is rated for a high current, it is really inferior to most opponents with lower current ratings. This drawback can show up in systems with huge amounts of system memory (it is powered by the standby source in Suspend-to-RAM mode) or with a large number of devices powered by USB in sleep mode, which is not a typical scenario.

Otherwise, the Kingwin Lazer LZ-850 is yet another high-quality, stable and even beautiful (in a system case with windows) high-wattage power supply.

Tagan SuperRock TG880-U33II

The Tagan website says that the SuperRock series is certified to comply with 80+Plus Bronze, but my sample belongs to an early batch that does not have that certification. There is nothing extraordinary about that. If the manufacturer finds that its existing platform can be easily upgraded to comply with new standards, why not do that?

Exterior Design

The Tagan TG880-U33II is cooled by a 120mm fan whereas most makers have already switched to 140mm ones, and this solution seems to be due to marketing rather than technical reasons. Otherwise, it is a conventional power supply of medium size and painted matte black. There is an operation mode indicator next to the mains connector.

The cables are not detachable.

The sticker “Certified by Tagan” looks funny to me. It takes a lot of self-confidence and shows great self-sufficiency to certify one’s own products!

Interior Design

The power supply is packed densely inside. There are a lot of large components: heatsinks, two transformers, and three parallel-connected high-voltage capacitors.

After last-generation models with small heatsinks and half-empty PCB, one might suspect the SuperRock of using yesterday’s components, but that’s not so. For example, there are two cards of switching DC-DC converters below one of the heatsinks. Thus, the output voltages of the TG880-U33II are regulated in the same way as, for example, in the Corsair HX850W: the main regulator yields +12V whereas the +5V and +3.3V voltages are generated by separate regulators.

Teapo capacitors are installed at the PSU output.

Specifications

The +12V rail is split into four “virtual” lines, 18 amperes each, which is not a good idea. A top-end graphics card like a GeForce GTX 480 or even 470 may overload such a line, triggering the PSU's protection. If you've got one graphics card, you should connect it to the PSU in such a way that different +12V lines led to the card's power connectors (the user manual says that two lines, 12V3 and 12V4, are connected to the graphics card connectors), but you may have problems with a SLI or CrossFireX configuration even though the PSU will offer enough of total output power.

Cables and Connectors

The PSU is equipped with the following cables and connectors:

There is nothing I can find fault with here. The PSU offers all necessary connectors.

UPS Compatibility

Working with my APC SmartUPS SC 620, this power supply was stable at loads up to 384 watts when powered by the mains and up to 300 watts when powered by the batteries. At a load of 330 watts the UPS would shut down in 10-15 seconds, reporting overload. An UPS with a sinusoid output voltage and a reserve of wattage may help here.

Output Voltage Stability

None of the voltages tracked violates the permissible limits at any loads, the +12V voltage even staying within a 2% deflection from the nominal level.

Output Voltage Ripple

The short spikes spoil the oscillogram somewhat, yet the PSU passes this test.

Noise

The PSU is cooled by a 120x120x25mm fan from Protechnic Electric. This company’s products do not enjoy a good reputation, but I must acknowledge I did not hear any unwanted noises from the fan of my PSU sample.

The PSU is average in terms of noisiness. The fan is as fast as 1000 RPM at loads up to 400 watts. At higher loads, the fan accelerates, reaching a maximum of 2000 RPM. The PSU gets really loud at 550-600 watts but cannot satisfy users who prefer silent computers even at lower loads. The difference from PSUs whose fans start out at 800 RPM or lower is clear in a home environment.

Efficiency and Power Factor

Although the PSU is not formally certified for the 80+Plus Bronze standard, it wouldn't have any problems getting one. In the 220V power grid I tested it in, its efficiency is no lower than 84% at loads ranging from 20 to 100% of its full output power.

Standby Source

The standby source copes with its job easily: its voltage lowers to 4.89 volts at full load whereas the permissible bottom level is 4.75 volts.

Summary

There are two drawbacks I can see in the Tagan SuperRock TG880-U33II and both are not going to be serious for most users. This model is somewhat noisier than most of its opponents and is not stable in pair with an UPS. Otherwise, it is a well-made high-wattage power supply suitable for a modern gaming PC.

Ultra Products X4 ULT-HA850X

This power supply is from the US-based Ultra Products which is known not only for its products but also for the lawsuit it filed two years ago against nearly all PSU makers, claiming that they violate its patent on the modular PSU design.

The Ultra X4 comes in a rather large box. The text on the box describes the contents as well as product features. Judging by the UL certificate number, this PSU is manufactured by Andyson.

Exterior Design

The X4 does not differ from other models save for the stamped emblem on its side. It is a rather compact matte-black box.

It looks more interesting at the back: people at Ultra Products must have decided to make full use of their patent and left not a single fixed cable here. Well, I don’t get why the mainboard and CPU cables should be detachable. The advertised opportunity to replace such a cable with a better one won't ever be used by 99.999% of users.

The connectors are not labeled, which is not good. When plugging a cable in, you have to look into the manual or guess what cable goes where by the shape and key of the connector.

Interior Design

Inside we see a rather typical modern PSU design without any innovations: active PFC, a single-step inverter, and dedicated voltage regulation based on magnetic amplifiers (saturated chokes).

There are Teapo capacitors at the output. They have a good reputation. The quality of assembly is overall blameless.

Specifications

Having a total output power of 850 watts, the PSU can yield only 720 watts via its +12V power rail. Considering that modern computers consume no more than 50 watts from the rest of the rails, the real output power of the X4 should be estimated at 770-800 watts. The good news is that the +12V rail is not split into “virtual” output lines.

Cables and Connectors

This PSU has the following connectors:

Included with the PSU are:

I like this selection of cables as they vary in length and amount of connectors, allowing you to pick up just the necessary ones for your particular system configuration. The cables are all long enough for a system case with a bottom PSU compartment.

I don’t like the lack of color coding. Every connector is the same black color, so it’s hard to differentiate them at one glance. It would be handier if the cable connectors (and the matching PSU connectors) were different colors as many other PSU makers do.

Velcro fasteners are pre-attached to the cables to help you lay them out neatly.

UPS Compatibility

Working with my APC SmartUPS SC 620, this power supply was stable at loads up to 375 watts when powered by the mains and switched to the UPS’s batteries normally, but the UPS would then report overload and shut down in a couple of seconds.

Output Voltage Stability

This PSU is unexpectedly poor in terms of +12V stability. This voltage varies from 12.1 to 12.55 volts depending on load. This is within the permissible range (the maximum is 12.6 volts), so this instability shouldn’t affect your computer's operation. As a matter of fact, PSUs with joint voltage regulation used to easily violate the permissible 5% deflection from the nominal level, but I have already got used to PSUs with dedicated voltage regulation and begin to grumble even at a deflection of 3 to 5%.

Output Voltage Ripple

The PSU passes this test well. The output voltage ripple is very low.

Noise

The fan has Ultra’s own sticker but its real maker is Young Lin Tech Co. It is a 135x135x25mm model.

The PSU is very quiet. The fan rotates at 725 RPM at loads up to 400 watts and its maximum speed is only 1300 RPM. It is audible but not irritating then.

Efficiency and Power Factor

The efficiency is just good: 87% at the maximum and about 85% on average. The power factor is unexpectedly low: it is only at 300 watts that it gets higher than 0.9. This parameter is unimportant for most users, though.

Standby Source

The standby source copes with its job just fine.

Summary

The Ultra X4 ULT-HA850X has a not-very-stable +12V power rail. Its real output power is some 50 watts below the specified one and its compatibility with UPSes is poor. On the other hand, this PSU differs from the competition with its very quiet operation and excellent selection of cables. Considering that the mentioned drawbacks are far from critical, it can be recommended for purchase.

XFX Black Edition XPS-850-BES

The last PSU to be discussed in this review comes from XFX which is mostly known for its graphics cards. The PSU market, already overcrowded with brands, seems to have some strange attraction to different manufacturers.

The PSU comes in a large box painted black and green.

Exterior Design

Despite its boastful Black Edition name, the XPS-850-BES is far less black than most of the above-described models. Its color is rather dark-gray and its fan is a nice-looking shade of green.

The case, especially the top panel, is shaped in a queer way but this has no practical function.

The PSU is modular and has eight connectors for power cables at the back: two for graphics cards and six for peripherals. The connectors are all the same color but differ in the number of pins, so you can hardly confuse them.

Interior Design

It is not simple to take this PSU apart. Taking the cover off, you can find that the fan is fastened to a separate frame rather than to the cover. The frame is secured to the case with self-tipping screws. This design has no effect on the airflows, but makes it more difficult to assemble the PSU or take it apart.

XFX designers do not seem to have tried to cut the cost as you can guess by the thickness of the back panel with the connectors. This is not a metal but plastic trim, yet it looks impressive anyway. And it serves a purely decorative purpose again. The connectors might have been hidden in an ordinary metallic case just as well by simply moving the card with them away from the back panel.

With the fan removed, I could easily identify a product of Seasonic. To be exact, it is the M12D series.

This PSU uses DC-DC converters to produce +5V and +3.3V voltages out of +12V. Otherwise, it is a standard enough model (it is the X series that Seasonic implements cutting-edge innovations in; we are going to publish a review of an X series power supply in near future).

Electrolytic capacitors from United Chemi-Con are installed at the PSU output. Polymer capacitors are used in the DC-DC converters.

Specifications

The PSU can yield nearly all of its output power via the +12V rail which is not split into any “virtual” lines and offers full freedom in connecting the load.

Cables and Connectors

This PSU is equipped with the following cables and connectors:

Included with the PSU are:

Again, one of the CPU cables is going to be idle in most computers whereas the available CPU cables may be a couple of centimeters too short to reach to the respective mainboard connector from a bottom PSU compartment in a large system case.

Otherwise, there are enough connectors and there are even two versions of HDD cables: with two and three connectors, so that you could choose what suits your configuration best.

UPS Compatibility

Working with my APC SmartUPS SC 620, this power supply was stable at loads up to 370 watts when powered by the mains and up to 360 watts when powered by the batteries. They had no problems switching to the UPS’s batteries.

Output Voltage Stability

Every voltage is stable, especially on the +12V rail.

Output Voltage Ripple

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

Noise

The PSU is cooled by an interesting fan from Adda that had large, nearly overlapping, blades. It should produce a good static pressure which is important for cooling a high-component-density power supply. The fan measures 135x135x25 millimeters and has a rated speed of 2200 RPM. A part of the impeller is blocked by a piece of plastic film to drive the air to the back of the PSU case.

The fan rotates at less than 700 RPM at loads up to 500 watts, which makes the PSU very quiet at that load range. Then, the fan speed grows up along with the load: the PSU is audible at 700 watts and higher and downright noisy at 800 watts. On the other hand, this load is rare in practical applications and is also associated with noisy components (such as GeForce GTX 480 or Radeon HD 5970 graphics cards), so the PSU can be viewed as quiet indeed.

Efficiency and Power Factor

The PSU is over 90% efficient at the maximum and 87% efficient at full load. It deservedly boasts its 80+Plus Silver certificate.

Standby Source

The standby source copes perfectly with its job. The difference between the minimum and maximum of its output voltage is less than 0.1 volts.

Summary

Taking to PSU production, XFX chose an experienced maker and did some good design work. The XPS-850-BES is a competitive product that can appeal to the customer with its original exterior, rich selection of connectors and good characteristics such as very quiet operation at low and medium loads.

Conclusion

Among the eleven power supplies I have tested today only one model stands out with its technical characteristics. It is the Antec TruePower Quattro which is cooled by an 80mm fan. It proved to be noisier than most of its opponents reviewed today but looks preferable to other high-wattage PSUs with small cooling fans. If you’ve got a server system case that does not allow to install a PSU with a 120 or 135mm fan, the Antec TPQ-850 is going to be a good choice for you. Therefore we are proud to award Antec TruePower Quattro TPQ-850 with our Editor's Choice title:

The rest of the PSUs cannot be easily categorized as each of them is good. I have not found serious defects in any of them. My comments are only reduced to "that's good enough but might be even better".

The PSUs do not vary much in size. There are no monsters with a length of over 20 centimeters like the Zalman ZM850-HP. They all deliver excellent electric parameters and high efficiency. So, if you don’t have some specific PSU requirements and just want to buy a high-wattage and high-quality model for your home gaming PC or high-performance workstation, you can base your choice on the availability and warranty conditions.

The only factor that might serve as a shopping guide is noisiness. If you want to have a quiet PSU, you may want to consider the Enermax MODU87+ (or the cheaper PRO87+), Huntkey HK901-11PEP, Kingwin Lazer LZ-850, Ultra X4 ULT-HA850X and XFX XPS-850W-BES. None of them has a fan speed higher than 800 RPM at low and medium loads, which makes them virtually silent. We are pround to award these power supply inits with our Recommended Buy title: