ATX Power Supply Units Roundup. Part X

This article is our report about five power supplies from well-known brands ranging from 500W to 800W . Two companies, namely Thermaltake and Enermax, are long known as PSU makers, but the other three are new names in the market of power supplies.

by Oleg Artamonov
09/29/2008 | 03:33 PM

Testing Methodology

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

 

You can also check Cooling/PSU section on our site for a complete list of PSU models we have tested in our labs.

BFG ES Series BFGR800WESPSU (800W)

BFG Technologies is a large retailer who is mostly active on the American market. We have reviewed this company’s graphics cards and now it’s time for us to check out its PSUs as well. It looks like a strong trend for graphics card, memory and cooler makers to begin to produce power supplies in addition to their main, traditional products.

This 800W ES series power supply is a senior PSU model from BFG. The manufacturer claims this series to have high efficiency. While the efficiency of most PSUs drops quickly at low loads, the ES series models ensure an 80% or higher efficiency even at a load of 10%.

The exterior of this power supply is quite traditional: a black glossy case with BFG logos pressed out in the side panels, and a large fan. The small vent grid in the side panel may catch your eye. Why is it there if a perforated external panel of the PSU is near?

Looking into the case, you can see an active PFC card near that grid. The card is photographed with the solder facing up. So, the additional ventilation is necessary to cool the PFC card more efficiently.

The real manufacturer of this power supply is Andyson. This name may be familiar to you by Hiper power supplies, for example. By the way, Hiper has changed its supplier recently and switched to Channel Well.

Andyson PSUs had raised my criticism for their low quality of soldering before. Fortunately, I didn’t find any problems on examining the ES-800.

There are some engineering solutions I do have gripes about, though. The first photograph of the interior of the PSU shows that it has as many as three high-voltage capacitors, one of which (it is black) stands upright on the main PCB while the other two (the blue and brown ones) are attached horizontally on additional cards.

The first “horizontal” capacitor is soldered to a small card fastened to two heatsinks. I was surprised to see that this capacitor was connected to the main PCB with one wire (to the “plus” pin) whereas the “minus” pin contacts, via a tinned spot and a self-tipping screw, with a heatsink (the rightmost heatsink in the photo) and then with the PCB. Andyson engineers may have had some thoughts about that, but I don’t think it is a good idea to use heatsinks as conductors.

The second “horizontal” capacitor is located on the active PFC card. It is photographed above with the components facing up. You can see this capacitor hold with its own leads only. It is not fastened in any other way. But the good practice is to fix every massive element of a PSU with at least a generous portion of glue.

I should note that I had two different versions of the ES-800 (I will explain this shortly), and the newer version did have a small drop of glue between the mentioned capacitor and the card. The overall reliability of design didn’t improve much from that, though.

Well, that’s enough about the drawbacks. They are not so substantial after all.

The PSU’s interior shows high mounting density (notwithstanding the use of surface-mounted components and additional cards) and very compact heatsinks that are no taller than the other components.

Some of the heatsinks are hard to see at first glance. There is nothing wrong with that, however. I have already reviewed power supplies from FSP Group in which the developer made the heatsinks smaller by increasing the number of load-bearing elements, transistors and diodes. In the ES-800, there are even two rows of elements on the tallest heatsink!

There are KZE series capacitors from United Chemi-Con at the PSU’s output. These capacitors have a good reputation and are often installed in top-quality power supplies.

A rather large additional card located near the side panel of the PSU carries circuitry for fan speed management and for monitoring the output voltages and currents.

The PSU is equipped with the following cables and connectors:

There is nothing I can find fault with here. The PSU offers all the connectors you may want. It can power up a SLI/CrossFire graphics subsystem in which each graphics card has two power connectors without any adapters.

The ES-800 is cooled with one 14cm fan (Globe Fan RL4Z B1382012H). There is no celluloid film on the fan. The problem of the dead zone which is solved in some other PSUs by blocking a part of the fan has a different solution here: there are vent holes in the internal panel of the PSU through which the air is blown black into the system case. The fan uses a 2-pin connection without the option of speed monitoring.

According to the label, the PSU can yield nearly all of its power, 780W out of the maximum of 800W, via its four +12V output lines. Like in most other PSUs, these are “virtual” line. There is actually one +12V power rail, with a maximum current of 65A, inside the PSU.

Take note that the different lines have different current limitations. Two of them allow a current of 36A – you can connect graphics cards, the most voracious components of the modern PC, to these lines. It means that each graphics card cable can be attached to a load up to 432W (the combined load on both cables cannot exceed 780 watts, of course) which is higher than the requirements of any existing graphics card, including the latest generation of ATI’s and Nvidia’s chips.

The PSU worked at full load normally, without overheat.

The first PSU we received from BFG for our tests was dated the 9th week of 2008 (you can learn the manufacturing date from the first four digits of the serial number glued to the PSU label). It turned to be a presale version that didn’t make it into shops due to one problem. Its output voltage ripple was too high.


PSU made on week 9

Indeed, the +12V rail is calm but the pulsation on the low-voltage rails is nearly twice as high as the permissible maximum of 50 millivolts even though the load on those rails was only 65 watts in the test (the remaining 700 watts with something were provided by the +12V rail).

It is nice that the manufacturer had been aware of the problem and suggested to replace the defective PSU before I reported the problem to them. According to BFG, there are additional smoothing capacitors in PSUs manufactured after the 15th week of 2008. It is the improved version that comes to retail.


PSU made on week 15

Alas, the problem didn’t vanish completely. The oscillogram shows that the output voltage ripple on the +5V and +3.3V rails is still above the permissible maximum although the short spikes are now much smoother.

The PSU shows good cross-load characteristics. The voltage on the +3.3V rail is the only one to exceed a 3% deflection but this happens only at a near-maximum load and when the load distribution is shifted towards the low-voltage rails, which is virtually impossible in a modern computer system.

The fan speed management is quite interesting here. There are a few bends in the graph. The fan starts out at a speed of 900rpm. It is quiet then, but not absolutely silent. The fan begins to speed up at a load of 200W and accelerates to 1100rpm, producing distinct noise. At loads above 550W the fan’s speed quickly grows to the maximum of about 1800rpm.

Thus, the BFG ES-800 is a quiet but not silent power supply. It is satisfactory in terms of noise at low and medium loads, but you may want to consider other models if you want silence.

Efficiency is supposed to be the strong point of the ES series.  It is good indeed. The PSU is 80% efficient at 10% from maximum load. The maximum efficiency is a superb 88%. The efficiency drops to 75% at a load of 50 watts, the minimum load in our tests, and this is somewhat better than 70% that most other PSUs show. On the other hand, the 5% difference at such a low load amounts to only 2.5 watts of saving.

The power factor graph is interesting, too. The power factor is as low as 0.65 at low loads, and oscillograms show that the PSU consumes the current with each second half-wave of the supply voltage. This may be the result of an adaptation of the PFC device for achieving maximum efficiency.

The BFG ES-800 is an ambiguous product overall. If it were not for the exceedingly high output voltage ripple, which is present even in the newer version of the PSU, this model might be called good as it provides a good selection of connectors, has a quiet fan, and offers stable voltages. Its efficiency is the most advertised quality of the ES series, and it is indeed high in comparison with other modern PSUs. However, the advantage over high-efficiency PSUs from other brands, including some models covered in this review, is not large at all.

Enermax MODU82+ EMD525AWT (525W)

The urge of every manufacturer of computer peripherals to begin to produce power supplies under his own brand is even hilarious now, especially as there are rather few actual makers of power supplies, but Enermax earned its reputation by producing PSUs. It is sad we don’t often have the chance to review its products.

To make our amends to the respected company, we are going to test the 525W MODU82+ power supply. This model belongs to the new series of Enermax’s products. The number 82 is supposed to indicate that the PSU not only meets the requirements of the 80 Plus program (it requires the PSU to have an efficiency of 80% or higher at loads from 20% to maximum) but surpasses them. Well, the high efficiency is not the only declared advantage of this PSU. It is also claimed to be very quiet at work. Let’s see…

The PSU has a standard case. Many other PSUs, and high-wattage models from Enermax too, have an increased depth, which may prevent you from installing them into a small system case. The dimensions are standard thanks to the 12mm fan.

But what about the promised silence? All the manufacturers are touting power supplies with 14cm cooling fans now. Well, I have to tell you that size doesn’t matter here. What matters is the developer’s experience. Every engineering solution has its pros and cons, and the choice of the cooling fan is no exception. The end result depends not on the fan size but on the design the developer created having such a fan in mind. For example, Antec’s very quiet NeoHE PSUs are cooled with one 80mm fan whereas the FSP Epsilon series have a very loud 120mm fan.

The PSU has a modular design. It has three fixed cables and seven connectors for detachable cables (five for HDDs and other peripherals and two for graphics cards). The connectors are shaped differently. You cannot confuse them even if you are plugging the cables in blindly.

By the way, Enermax also offers the PRO82+ model which is exactly alike to the MODU82+ in its specs but has non-detachable cables and is cheaper as the consequence.

The interior design of this PSU seems to be ordinary enough. It has one power transformer, an active PFC device (its choke can be seen at the left edge of the PCB, near the couple of large high-voltage capacitors), and dedicated voltage regulation. The component mounting is neat and tidy overall. I have no complaints about that.

The controller of the PFC and the main regulator is based on a Champion CM6802BG chip. There are a couple of 180µF capacitors for a voltage of 400V in the PSU’s high-voltage section. This reminds me of power supplies without active PFC in which capacitors always stood in twos. Here, it is just an engineering solution concerning the component layout: the capacitors are connected in parallel and work as one 360µF/400V capacitor. KZE series capacitors from United Chemi-Con are installed at the PSU’s output.

The PSU is cooled with a nearly standard 120x120x25mm fan. The fan label points at Enermax as the maker, but it must be some third company, of course.

As I mentioned above, the fan is not absolutely standard. It has two peculiarities. First, the ends of its blades are folded in a special way. Well, I am not as versed in aerodynamics as to comment knowingly upon the value of this folding in terms of noise and cooling efficiency.

Second, the fan uses a 4-pin connection. Such fans have become a de-facto standard in CPU coolers but it is the first time I see one in a power supply. The first three pins provide power (ground and +12V) and a tachometer output that allows to measure the speed of the fan but not to regulate it. In a typical 2- or 3-pin fan the speed can be varied by lowering the supply voltage. It is generally accepted that the fan speed can be lowered to 40-50% from the rated one without the risk of stopping the fan. In a 4-pin fan the additional wire is needed for speed adjustment. The guaranteed range of this adjustment is broader than with the voltage-based regulation.

The potential problem is obvious: if you want to replace the fan for some reason, it won’t be easy to find a 4-pin model of the same form-factor. 4-pin fans (for example, from Scythe) already sell separately from coolers but the choice isn’t wide.

The PSU is equipped with the following cables and connectors:

Included with the PSU are:

The selection of connectors is standard and the same as you get with any other PSU described in this review, but I’d like to make one comment concerning the type of the SATA connectors.

The photo above shows the two possible designs: a straight connector on the left and a T-shaped connector on the right. In a modern computer hard disk drives are often positioned crosswise in the system case, so the T-shaped connector is handier. It is shorter and doesn’t need you to bend the cable so that the latter wouldn’t press against the side panel of the case. Alas, every SATA connector of the MODU82+ is of the straight variety as in the left photo. On the other hand, the straight connector is somewhat handier if you need to connect a few HDDs in a system case where they are positioned in the classic, lengthwise, way.

The PSU can provide up to 480W (40A) across its +12V rail which is split into three “virtual” output lines each with a load capacity of 25A (300W). This allows you to connect any modern graphics card to only one power cable.

The PSU worked without problems at its full load of 525W.

The output voltage ripple was low on every power rail at full load. It is twice or thrice lower than the permissible maximum.

There were also small low-voltage pulsations but the PSU meets the requirements of the industry standard even if you add those in.

The cross-load diagram of this PSU is a treat for the eye. None of the three tracked voltages exceeds a 3% deflection at any load combination. What is especially good, the +12V voltage is very close to 12 volts even at the maximum permissible load for that power rail. So, this PSU can easily power up a hardware configuration with a power draw of nearly 525W. And it is not so easy even to assemble such a configuration as typical computers need much less power.

The PSU was brilliant in the fan speed test. Its fan started at less than 500rpm. You can’t hear the fan at such a speed unless you put your ear close to it in a very quiet room. The speed grows up along with the load, but only reached 1000rpm at 400W. The fan had a speed of only 1260rpm at full load. Although it is audible at such a speed, its noise is within comfortable limits.

The PSU also features superb efficiency. It is 88% efficient at the peak and 85% efficient at full load. Do you remember the above-discussed BFG ES-800 which claims to deliver high efficiency at low loads? Of course, it is not quite correct to compare 525W and 800W power supplies, yet I can note that the MODU82+ is about 80% efficient at a load of 50W whereas the ES-800 is about 76% efficient at that load.

So, Enermax’s new series of PSUs is not just a success. It is brilliant. The MODU82+ delivers superb electrical parameters, high efficiency, stable voltages, all the necessary connectors, and quietest, near silent, operation. This PSU is going to be a perfect choice for any medium and even top-end PC configuration, from a HTPC to a gaming station. Moreover, the MODU82+ is not only as quiet as the recognized leaders like Zalman ZM460B-APS or Seasonic S-12 but may even prove superior to them in terms of noisiness.

If the price of the MODU82+ seems too steep to you, you may want to consider the cheaper version called PRO82+ that comes with non-detachable cables.

SuperTalent Atomic Juice PS-700 (700W)

Super Talent may be familiar to you as the maker of good USB flash drives.

But today, you will discover this company as the manufacturer of power supplies.

In fact, the appearance of this PSU is most indicative of its real manufacturer: a compact, standard-size case with characteristic vent slits at the bottom of the side panel.

The interior design leaves no place for doubt, too. Of course, this is a FSP Epsilon you may be familiar with by our reviews. In the OEM version it is called FSP700-80GLN.

PSUs of this series can be identified by the three heatsinks only one of which has any ribbing at all. The other two are absolutely smooth. However, there are no overheat-related problems as I have repeatedly made sure of in my tests. The manufacturer made up for the small dissipation area of the heatsinks by using a redundant amount of semiconductor components. Diode packs at the output stand in twos or even in fours. It is mainly done to reduce the weight of the PSU. In Europe, this lowers the value of the tax on electronic equipment.

A 470µF/420V capacitor from OST is installed on the PSU’s input. At the output there are capacitors from CapXon and from OST’s RLP series. The main regulator and the active PFC device are based on a Champion CM6800G chip. The standby +5V source is based on a Fairchild FSDM0265R.

The PSU is cooled with a 120x120x25mm fan (Yate Loon D12BH-12) with a rated speed of 2300rpm.

The fan is highlighted with four orange LEDs at work. This color doesn’t match the blue case of the PSU but agrees with the coloring of its box.

The total output power of the PSU is 700W and it can yield 680W via the +12V rail divided into four output lines.

The PSU is equipped with the following cables and connectors:

The PSU is obviously meant for one graphics card (or two cards each of which has only one power connector) although it might easily power up a couple of top-end cards in SLI/CrossFire mode. Alas, you have to use adapters from Molex connectors in that case.

A light smell of hot insulation could be felt when the PSU was working at a load of 680W but there were no other problems.

The output voltage ripple at full load is overall acceptable but individual spikes on the +5V and +3.3V rails are higher than the permissible 50 millivolts. So, the PSU is in fact at the limit in this parameter.

The cross-load characteristics do not impress. Although green dominates the zone typical of modern PCs (a high load on the +12V rail and some 50-60W on the +5V and +3.3V rails combined), I have to note that the PSU doesn’t deliver the declared load of 155W on the low-voltage rails because the +5V voltage sags below the permissible limit (4.75V) much sooner.

But it is the noise level that proves to be the main problem with this PSU. The Atomic Juice’s fan is loud even at minimum load, working at 1300rpm. Its speed grows up linearly together with the load, reaching 2000rpm (the controller must be unable to give a higher voltage to the fan). As a result, the PS-700 is so loud that I wouldn’t recommend it even to undemanding users. It will surely drown the voices of other PC components in its annoying hum.

A few years ago new power supplies from FSP used to feature high efficiency, but now they look nothing but modest in comparison with their current opponents. This PSU is 85% efficient at the peak and 82% efficient at full load. I have to admit that the Atomic Juice has the worst result among the five PSUs covered by this review in terms of efficiency.

In fact, the Super Talent Atomic Juice PS-700 might be a good mainstream power supply if it were not for its noisiness. I have no complaints about the quality of manufacture. The selection of connectors is suitable even for an advanced gaming configuration. The electrical parameters are not outstanding, yet acceptable. Alas, the PS-700 produces distinct noise even at minimum load, i.e. in idle mode virtually. This noise is so distinct that I would not recommend this power supply even for users who are not fastidious about noise, just because there are a lot of models available on the market that are going to be far more agreeable to your ear.

Thermaltake Toughpower QFan 650 A (W0163RU, 650W)

Although Thermaltake began as a developer of cooling systems, Thermaltake-branded power supplies are nothing new already. Thermaltake has been turning out power supplies for a few years, developing a few product series and introducing a number of individual models in this time.

Packaged into a large white box, this model is expected to differ from its opponents with incredibly quiet operation. The manufacturer makes this promise thanks to the special design of the fan called QFan. So, this PSU should make a good opponent to the Enermax MODU82+.

The first part of the QFan technology is that the PSU has horizontal slits around the perimeter opposite the sides of the fan. Otherwise, the PSU looks quite ordinarily, resembling the Purepower RX series from the same brand except that a thick punched-out fan grid is now replaced with a thin wire one.

The PSU features a modular design with seven connectors for power cables of HDDs, optical drives and CPU. Two cables are fixed: a mainboard cable and a graphics card cable with an 8-pin connector (you are supposed to use the included adapter if your graphics card has a 6-pin power plug only).

The interior design of the PSU copies the Purepower RX series. The real manufacturer is Channel Well (CWT). This company provides power supplies not only to Thermaltake but also to Corsair, Hiper, Gigabyte and other renowned brands.

The PSU is based on a CM6800G chip that combines PFC and main-regulator controllers. The load-bearing elements – transistors and diode packs – are distributed among three rather large heatsinks. One heatsink carries the components of active PFC. The second heatsink carries the transistors of the main switch. And the third heatsink carries the diode packs of the output rectifier.

There is a 400V/390µF capacitor from Hitachi at the PSU’s input. Samxon’s capacitors are installed at the output.

Of course, the most exciting part of this PSU is its fan. It is an Everflow R121225BL with a standard form-factor of 120x120x25mm and a rated speed of 2000rpm.

The fan is in fact case-less. The motor and impeller are fastened to a frame that doesn’t have side panels. There are only four poles for self-tipping screws that fix the fan within the PSU case.

As I wrote above, there are horizontal slits around the case. You can see the fan’s impeller through them.

According to Thermaltake (the picture above is taken from the company’s website), the fan takes the air in through those slits, thus increasing the cooling efficiency.

Well, but I think that when a fan is rotating, the centrifugal force makes the air move outward and not in some other way. This is the operating principle of blowers that are often employed to cool graphics cards: their impeller is driving the air away from the rotation axis rather than along it.

Then, it is also clear that a high-pressure zone is developed under the fan’s impeller when the fan is rotating. And of course, the outside air can’t be forced in there. The air can only move out of there to the outside!

So who is wrong about these basic things, me or Thermaltake? I performed a small experiment by placing a piece of paper on a side panel of the operating PSU:

It is clear that the paper goes off the PSU rather than clings to it. It means that the air is going out of the slits but not into them. Alas, the picture at the Thermaltake website is quite misleading.

As a matter of fact, I wanted to make a snapshot of a burning match. This is a standard way of identifying weak airflows. But the airflow coming out of the QFan is not weak. It just blew the fire off the match!

The noise properties of the QFan will be discussed shortly. Right now I’ll continue to describe the PSU.

It is equipped with the following cables and connectors:

Included with the power supply are:

So, this is a good selection of cables but you’ll have to use an adapter for the fourth graphics card connector if you are assembling a SLI/CrossFire graphics subsystem. Moreover, two CPU power connectors are only necessary for a few advanced mainboards targeted at servers and workstations. In most computers the extra connector on the appropriate cable will just be a nuisance. It would be handier if the kit included two different cables, one with an 8-pin and the other with a 4-pin connector.

The PSU has a total output power of 650W and can yield up to 624W across its +12V rail divided into four “virtual” output lines, each rated for 18A (216W).

I found no problems with the PSU when it was working at full load.

The output voltage ripple is within the permissible limits at every of the PSU’s three main output rails.

The +12V voltage is just ideal, deflecting by no more than 1% from the nominal value at any load, from 50W to 650W. The +5V and +3.3V voltages vary more, but only exceed a 3% deflection at near-maximum loads. None of the voltages exceeds the permissible deflection of 5%.

As for the noise factor, the power supply is indeed silent at low loads, its fan rotating at less than 800rpm. However, the fan accelerates rapidly at loads higher than 200W, reaching 1000rpm (which is roughly the limit of quiet operation) at a load of about 270W. Besides the hiss of the airflow, the fan is buzzing audibly.

Thus, this PSU can stand no comparison with the Enermax MODU82+. The Enermax is quieter through the entire range of loads. And while the Toughpower QFan can be called comfortable at loads below 250W, its fan speed grows so rapidly thereafter that the operating PSU becomes surely noisy. Of course, it is far quieter than the wailing fan of the SuperTalent Atomic Juice PS-700, yet there is no talking about “Extremely Quiet” as promised by the manufacturer.

Comparing the Toughpower QFan with its closest relatives in Thermaltake’s product line-up, namely Purepower RX and ordinary Toughpower, the QFan is quieter at low loads only. When working at high loads, these PSUs produce about the same amount of noise.

The QFan is no record-breaker in terms of efficiency, but its result is good: a peak efficiency of 86% and an efficiency of 84% at full load. I should note again that these results are no different from the efficiency of the Purepower RX and Toughpower PSUs.

Summing everything up, I can’t really say that the Thermaltake Toughpower QFan is a poor product. On the contrary, it delivers the declared electrical parameters, offers a good selection of connectors, and boasts problem-free operation. The problem is that the QFan is actually no different from the Purepower RX and Toughpower series which have been selling for long and reviewed regularly although it claims to be exceptional. Its fan design is even questionable in terms of noise reduction (the aerodynamic noise of the air passing through the side slits is rather going to worsen this parameter whereas the leakage of the air sideways lowers the effective performance of the fan) and is presented by the manufacturer in a totally misleading way: the laws of physics and the common sense suggest that the air is going out of the PSU but the picture at the Thermaltake’s website shows exactly the opposite. Added to that, the fan of our sample of the PSU would buzz audibly at a speed of 1000rpm and higher. This may have been a defect of the particular sample, though.

Thus, the Toughpower QFan is quieter than any other model of the Toughpower and Purepower RX series at low loads and comparable to them at medium and high loads. It cannot offer serious competition to truly quiet power supplies such as the above-discussed Enermax MODU82+.

Xigmatek “No Rules Power” NRP-MC651 (650W)

The relatively young company Xigmatek, founded in 2005, has something in common with Thermaltake whose power supply I have discussed in the previous section. Both companies began their business by producing cooling systems.

Today, Xigmatek offers power supplies, too. This model features original packaging. Its black cardboard box is wrapped into a cover painted the color of jeans.

And when you take a look at this power supply, you can see right away that the similarity between Thermaltake and Xigmatek goes beyond the type of products produced. In fact, the two power supplies from these brands covered in this review differ in one thing only: the NRP-MC651 doesn’t have the exclusive QFan slits around its perimeter.

The reason for this striking similarity is obvious: power supplies for both Thermaltake and Xigmatek are produced by Channel Well. This manufacturer has enlarged considerably its market share by producing PSUs for well-known retail brands. That’s why you can see power supplies from CWT in nearly every of our reviews.

The NRP-MC651 is a modular power supply that has fixed cables for mainboard, processor and two graphics cards. There are seven connectors for the rest of components. The connectors differ in shape and color, so you can’t do anything wrong. For more convenience there is a picture with instructions what cables go where.

 

The internals doesn’t differ much from those of the Toughpower QFan except for the shape of the heatsinks which are flat in Thermaltake’s power supply and more intricate here. The circuit design hasn’t changed. The PSU is based on a Champion CM6800G controller and features both active PFC and dedicated voltage regulation. A 390µF/400V capacitor from Hitachi is installed at the PSU’s input. Instead of Samxon capacitors as in the Thermaltake product, the PSU’s output has KZE series capacitors from the more renowned United Chemi-Con.

The assembly and soldering are very neat. I have no complaints about that.

The PSU is cooled with a 140x140x25mm fan (Yate Loon D14BM-12) whose case and impeller are made from translucent plastic and highlighted with four LEDs at work.

The PSU has the following cables and connectors:

Included with the power supply are:

So, this is a sufficient selection of cables. The PSU allows to connect two graphics cards with two power connectors on each without any adapters.

The label says that the PSU has a total output power of 650W and can provide up to 624W (52A) across its +12V rail divide into four output lines. The load capacity of the +3.3V and +5V rails is quite high, up to 180W. A real-life modern PC system can hardly consume more than one third of that amount of power.

The PSU passed my full-load test successfully.

The output voltage ripple on every of the PSU’s three outputs tracked in this test is about half the permissible maximum at full load. Take note that while the similar PSU from Thermaltake had individual short spikes of voltage, but we don’t see much of them here. Is it the consequence of the use of capacitors from United Chemi-Con instead of Samxon?

The cross-load diagram looks good: the +12V voltage is ideal. The +5V and +3.3V voltages deflect by 3% only at near-maximum loads which are impossible in a real PC. None of the voltages reaches a 5% deflection which is considered critical.

The fan speed is constant at somewhat lower than 1000rpm at loads below 200W. The PSU is not quiet then, but quite comfortable. When the load grows higher, the fan accelerates rapidly, reaching the maximum speed (1740rpm) at 450W. Of course, the amount of noise is increased greatly. As a result, the NRP-MC651 is acceptable in terms of noisiness at low loads and rather noisy at medium and high loads. I can note that its acoustic parameters are almost identical to those of Thermaltake’s PSUs and other models developed by CWT on the same platform.

The efficiency and power factor measurements do not produce any surprises. The PSU is 71% efficient at minimum load, 85% efficient at medium load, and 83% efficient at full load. This is quite an ordinary result which is somewhat inferior to the best models of PSUs from other makers.

Thus, the Xigmatek “No Rules Power” NRP-MC651 is yet another representative of the popular series of PSUs manufactured by Channel Well for many retail brands. Its parameters make it almost indistinguishable from such PSUs as Thermaltake’s Purepower RX and Toughpower series, Corsair’s CMPSU-750TX and many others that are manufactured at CWT’s facilities on the basis of the same platform.

The NRP-MC651 has very good electric parameters and offers a full selection of cables and connectors to allow you to assemble almost any configuration without adapters. The only drawback I can find in this model is that its noisiness varies from acceptable to rather noisy depending on load.

Conclusion

I guess this test session is the rare occasion when I can definitely name one absolute leader. It is the Enermax MODU82+ power supply. Besides neat assembly and superb electric properties, it proved to be so quiet that it was virtually silent at low and medium loads and quite comfortable at full load. Surely, the MODU82+ won’t be the noisiness component in a system that can load half-a-kilowatt power supply.

Thermaltake wanted to compete with Enermax but proved to be a disappointment. The Toughpower QFan W0163RU is almost no different from cheaper Purepower RX and Toughpower (without the QFan suffix) series models, being only superior to them in terms of noisiness when working at low loads. The QFan technology itself is rather questionable and the QFan-enabled power supply is not the quietest available. So, if you want a high-quality medium-noisiness power supply, you shouldn’t pay extra for QFan. And if you want to have complete silence, you should consider products from other manufacturers instead.

The Xigmatek “No Rules Power” NRP-MC651, manufactured at Channel Well’s facilities too, is almost exactly alike to Thermaltake’s power supply in its electrical section. The difference between the two is about noise: the NRP-MC651 is average in terms of noisiness even at low loads. It will satisfy most users, but not a lover of silence.

Besides the Xigmatek, power supplies from two more companies have debuted in our reviews. I mean the BFG ES-800 and the Super Talent Atomic Juice PS-700. The former disappointed me somewhat with the choice of the developer and manufacturer (Andyson had been criticized by me before for low assembly quality). Moreover, the voltage ripple at the PSU’s output exceeded the permissible limit.

While the debut of BFG is questionable, the entrance of Super Talent into the power supply market is unfortunately a total failure. The PS-700 model, manufactured at FSP Group’s facilities, turned to have mediocre electrical parameters and but also produce so much noise that I wouldn’t risk recommending it even to undemanding users.