600-850W Power Supply Units Roundup

In this roundup we will discuss six power supply units that offer sufficient capacity for a home computer system. These are the products from Antec, Enhance, Hiper and Scythe.

by Dmitry Vasiliev
11/16/2011 | 01:32 PM

Although the power supply units I am going to review today have different wattage ratings, ranging from 600 to 850 watts, they are all designed for an above-average computer configuration. A typical office or mainstream home PC (with an entry-level CPU and graphics card, one or two HDDs and an optical drive) is going to be perfectly satisfied with just a high-quality 400-watt PSU.


So, I will be talking about products from four brands (two from Hiper and Scythe each, one Antec and one Enhance) which are meant for rather advanced configurations with high-performance CPUs and graphics cards. Those of them with the highest wattage ratings should even be able to cope with a gaming PC that has a multi-GPU graphics subsystem. But besides the wattage rating, there is the question of quality. That’s the issue I’m going to check out in this review.

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. If you feel overwhelmed with the numbers and terms this review abounds in, refer to the Methodology.

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

Hiper M600

Products of High Performance Group almost vanished from shop shelves some time ago, raising concerns about the future of this maker of rather good PSUs and system cases. Having changed its owner, the company is on the market again, and with a brand-new PSU line-up. It’s high time for us to test some of them.

First goes the M600, a medium model from Hiper’s mainstream series.

The M600 comes in a glossy cardboard box together with a power cord, two sets of fastening screws (ordinary and thumbscrews), a few reusable cable straps and a user manual. Quite sufficient accessories for a PSU.

Exterior Design

The Hiper M600 has a rather ordinary appearance except for the red color of its fan highlighting: a matte black case, a black grille above a translucent fan, a meshed back panel. The rest of the panels are blank. Every cable is hidden into a black nylon sleeve.

The PSU is rather compact, its case just matching the size of the cooling fan. There is quite a lot of free space inside as you will see shortly.

The PSU looks nice when working, but you may want to make sure its red highlighting matches the highlighting of your other fans.

Circuit Design

There is nothing extraordinary under the hood. The M600 represents a rather typical and inexpensive design without dedicated voltage regulation and with active PFC.

The PCB that all the components are mounted on is quite small, leaving some free space at the front and back of the case; the component density isn’t high.

The PSU uses rather high-quality Teapo capacitors at the output and less expensive Jun Fu capacitors elsewhere.

The Hiper M600 is based on the Andyson Performance F series platform.

Cables and Connectors

The M600 is equipped with the following cables and connectors:

The cables aren’t very long, making the M600 not the best choice for large system cases, especially those with a bottom PSU bay and a dedicated cable compartment. On the other hand, the selection of connectors is quite sufficient and it’s handy that most of the peripheral cables have connectors of different types.


The Hiper M600 can hardly impress you with its specs. It can only give you 432 watts across the +12V power rail, which has the highest load in modern computers, out of the total of 581.5 watts it can deliver across the +3.3, +5 and +12V rails combined (the -12V line and +5V standby source provide the remaining 18.5 watts to meet the 600-watt specification).

On the other hand, we can note that the specifications allow for maximum load on all of the power rails simultaneously, which is an unrealistic situation. It seems that people at Hiper wanted to kill two birds with one stone: to write a high wattage rating into the product specs and to do so without saying any blatant lies. With such a modest max load on the +12V rail, this PSU would be marked as 500 or even 450 watts by a first-tier brand because it can hardly yield any more in a real-life computer, even if it fully complies with its own specs.

The maximum short-term load the PSU supports is specified to be 650 watts.

Temperature and Noise

This PSU is cooled by a fan from the Chinese maker Fujian. Although the brand is rather obscure, the 135mm fan is high quality. It doesn't produce unwanted sounds and has bright highlighting. Of course, it may prove to have a shorter service life than its more renowned counterparts, but again, the Fujian FJ1352512SH fan is blameless when new.

The fan starts out at a speed of about 860 RPM and keeps it until a load of 170 watts. Then it begins to accelerate smoothly. The fan doesn't reach its maximum possible speed, though. When the PSU is under maximum load, the fan rotates at 1700 RPM (the same fan would reach over 1800 RPM in the Hiper K800 PSU).

Although the fan isn’t slow at medium and high PSU loads, its noise remains within comfortable limits until a speed of 1300-1400 RPM (at a load of about 400 watts).

The cooling is quite efficient. The difference in temperature between the incoming and outgoing air increases at higher loads but is never larger than 10°C.

So, the Hiper M600 can hardly satisfy you if you need a perfectly silent computer, but most users are going to feel comfortable with it.

UPS Compatibility

Notwithstanding its active PFC, the M600 showed good compatibility with my APC SmartUPS SC 620. The pair was stable at loads up to 315 watts when powered by the mains and switched to the UPS batteries normally at the same load.

Output Voltage Stability

The PSU didn’t quite make it to its specifications. It wasn't stable when the combined load on the +5 and +3.3V rails was over 140 watts. When the load reached the specified maximum of 150 watts, the Power Ok signal would vanish, causing the PSU to shut down. This is not a serious downside, though. A modern computer can hardly want more than half that power across those two rails.

The +12V voltage deflects more than 3% from its nominal value at high loads on the +3.3V and +5V rails combined or when the load on the +12V rail is less than 25 watts, both being unlikely situations. By the way, the PSU would start up normally at zero load.

The +5V voltage goes out of the 3% limits when the load on the +5V rail is either too low (below 15 watts) or too high (over 80 watts). Neither case is typical of modern PCs.

The +3.3V voltage is blameless. It only deviates by 3% when all of the power rails are loaded to their maximums.

Output Voltage Ripple

The high-frequency voltage ripple is strong on each line, with occasional spikes shooting beyond the permissible maximums. Still, I’d say that the PSU complies with the industry standard in this parameter.

The same goes for the voltage ripple at the double frequency of the power mains.

Efficiency and Power Factor

The Hiper M600 delivered rather ambiguous results in this test.

Its active PFC is far from efficient as the power factor hits 0.9 at a load of 422 watts only and reaches 91.3% at full load. This is better than any passive PFC, though. Besides, this parameter is not important for home users.

Contrary to the power factor, the efficiency factor of this PSU is quite high. Despite the lack of any 80+ certification, the Hiper M600 meets the 80+Bronze requirements, being 85% efficient through the larger part of its load range. Well, Andyson’s native PSUs based on this platform are 80+Bronze certified, actually.

+5V Standby Source

The standby source copes with its job without any problems.


The Hiper M600 is quiet at low and medium loads, efficient (despite the lack of official certification, it meets the 80+Bronze requirements), compatible with UPSes, and offers a good selection of connectors for a PSU of its class.

On the downside are the rather low load capacity of the +12V rail, low-efficiency active PFC, and short cables (especially for system cases with a bottom PSU bay).

Thus, this model can be recommended for not-very-advanced configurations assembled in not-very-large system cases, especially as Hiper puts an attractive price tag on it. But you'll want something better for a serious gaming station, of course.

Scythe Stronger 600 W Plug-in

A well-known maker of cooling systems, Scythe has been changing its product range recently. The changes have been so radical and fast that the Stronger 600 W Plug-in has been put out of production even as I have been preparing this review for publication.

Well, since the PSU is already tested, I guess you may be interested to learn how good (or bad) it was and why it left the assembly line so quickly.

The Stronger 600 W Plug-in comes in a matte cardboard box peppered with various slogans and stickers describing its advantages.

Exterior Design

There are a few nuances that set the Stronger 600 W Plug-in apart from ordinary PSUs.

Its case is covered with original paint which is smooth but not glossy. There is a rather untidy square cutout the fixed pair of cables goes out from. And there are two 3-pin connectors for fans. The PSU is supposed to intelligently regulate the speed of the connected fans depending on load but I didn’t check this feature out.

Otherwise, the exterior design is standard: a silvery grille with product name above the fan and a honeycomb grid of the back panel. The rest of the panels are blank.

Circuit Design

The characteristic shape of the heatsinks betrays an Enhance platform.

Indeed, the Stronger 600 W Plug-in is almost identical to the Enhance ATX-0260GA we tested earlier.

There wasn't anything extraordinary about the Enhance ATX-0260GA when we reviewed it in 2009: active PFC, no dedicated voltage regulation and no special features. Based on the same platform, the Stronger 600 W Plug-in can’t show us anything in terms of cutting-edge technologies in 2011.

Like the mentioned Enhance, the Scythe has Teapo capacitors, rated for an operating temperature up to 105°C, at the output.

The PCB is as small as the Hyper M600’s, but there is an additional card with connectors for detachable cables at one side.

Cables and Connectors

The Scythe Stronger 600 W Plug-in is equipped with the following cables and connectors:

The cables, especially the 4+4-pin mainboard cable, may prove to be too short for large system cases. It is impossible to plug a cable into a wrong connector because they differ in the position of the keys.


The Stronger 600 W Plug-in specifications are the same as the Enhance ATX-0260GA ones except that the maximum current on the first +12V line is increased from 25 to 35 amperes.

The combined load on the two +12V lines hasn’t changed and remains at a rather low level: as much as 100 watts of the specified output power are distributed among the secondary power rails. In fact, I'd view this PSU as a 500W one.

Temperature and Noise

Considering Scythe’s main line of business, it would be odd to encounter something other than Scythe's own fan inside.

Indeed, the PSU is cooled by a Scythe SM1425SL12PM fan. Its mounting holes correspond to those of a standard 120mm fan whereas its impeller is as large as that of 140mm fans.

What does it mean for the end-user? Well, if this nonstandard fan fails, you will be able to replace it with any 120mm one. However, the efficiency of the replacement fan will be lower due to its smaller impeller as well as to the larger cutout in the PSU case.

The fan starts out at 800 RPM and keeps this speed until a load of 270 watts. Then the speed grows up linearly, reaching 1800 RPM at full load. The PSU becomes rather noisy at loads above 400 watts.

The Scythe SM1425SL12PM is about as noisy as the above-discussed Hiper but quieter than the original Enhance which used to increase its fan speed linearly right from the start.

UPS Compatibility

The Scythe SM1425SL12PM was stable with my APC SmartUPS SC 620 at loads up to 360 watts (when powered by the mains) and 300 watts (when powered by the batteries). The pair switched to the UPS batteries without problems.

Output Voltage Stability

The cross-load diagram of this PSU doesn’t look neat. Unfortunately, it is the +12V rail's fault.

The most advanced of our reference PC configurations (marked with the number 3 in the diagram) wouldn’t work with this PSU due to the voltage sag on the +12V rail, even though the PSU should be able to power it up according to its specs. The +12V voltage depends too much on the +5V load.

The +5V voltage diagram may be frightening at first sight with its abundance of yellow and orange, but this voltage is actually close to ideal in the real-life load range. Our first two reference configurations are within the bright-green 1% zone, and the third one would also be there if it were not for the +12V rail.

There are no problems with the +3.3V voltage as it deflects no more than 3% from the face value.

Output Voltage Ripple

There is conspicuous output voltage ripple on the +5V and +12V rails but it’s within the permissible limits. There are no short-term spikes above those limits.

The same goes for the low-frequency voltage ripple.

Efficiency and Power Factor

The PSU’s power factor is somewhat lower than that of typical PSUs with active power factor correction.

The efficiency is high at low and medium loads (above 85% within the range of 70 to 400 watts) but sags at high ones (only 81% at full load). The native PSU from Enhance was somewhat better in this respect.

+5V Standby Source

The standby source copes with its task.


The cross-load test shows the reason why this model has disappeared from Scythe's product range. The +12V voltage sags too much when the +5V rail’s load is rather low and this can hardly be a defect of the particular sample. An Enhance PSU with the same circuit design as the Stronger 600 W Plug-in produced the same picture in our earlier review.

Otherwise, the PSU is good, if not perfect. But what's the use of all of its benefits if it fails to perform its main duty, which is to deliver stable power to computer components?

Antec Neo ECO 620C

As opposed to the other tested products, this one was taken out of an Antec Sonata IV system case, but the manufacturer’s website says it can be purchased separately. Antec positions its Sonata series as silent solutions, so I am curious as to how the bundled PSU complies with that positioning.

Exterior Design

There is nothing special about the exterior of this PSU.

It’s got a matte steel-gray case with the manufacturer’s logo stamped on its side. The cables are all fixed and sleeved. The black cooling fan is covered with a black grille.

Everything is standard here except for the color of the case (as a matter of fact, bundled PSUs don’t usually get painted at all; this exception must be due to the model's availability as a standalone retail product).

The back panel of the case is meshed and has a mains connector and an On/Off switch. The other panels are blank (except for the one with a fan).

Circuit Design

The interior of the Antec Neo ECO 620C resembles Seasonic’s M12-II and S12-II Bronze models with its beige-colored PCB, characteristically shaped aluminum heatsinks and identical component layout.

Judging by the non-modular design and specs, the Neo ECO 620C is based on Seasonic’s 620W S12 series model.

Compared to the more expensive M12-II series, the S12-II (and the Neo ECO 620C, too) lacks detachable cables and has a shorter case.

Well, we can find certain differences here. Seasonic employed United Chemi-Con's KZE series capacitors in its products whereas the Neo ECO 620C mostly has Teapo capacitors (there is also one Su’scon and one large Nippon Chemi-Con capacitor at the output).

Like a regular midrange PSU without any pretense, the Neo ECO 620C has active PFC and lacks dedicated voltage regulation.

Cables and Connectors

The Antec Neo ECO 620C is equipped with the following cables and connectors:

The cables are somewhat longer that those of the original Seasonic. The extra length of the mainboard's 4+4-pin cable is going to be appreciated by owners of large system cases with a bottom PSU bay.


The Antec Neo ECO 620C has the same specs as the Seasonic S12-II Bronze with a wattage rating of 620 watts. And they are quite up to today’s requirements, too. The PSU can give you 576 out of its full 620 watts across the +12V rail.

The difference boils down to the lack of 80+Bronze certification (the basic 80+ certificate the PSU sports is formally useless for 220V mains).

UPS Compatibility

Like its Seasonic progenitors, the Antec Neo ECO 620C refused to be compatible with my UPS. They were stable at loads up to 370 watts when powered by the mains but couldn’t work even at 280 watts on the UPS batteries.

Output Voltage Stability

The cross-load diagram is almost the same as that of the Seasonic M12-II 620 Bronze, which might be expected considering their identical circuit design.

The voltage on the +12V rail deflects the most from the default level either when there is a high load on the +12V rail and a very low load on the other rails or vice versa. In the range of real-life loads this voltage doesn't deflect more than 2%, though.

The +5V voltage goes further from the default level as the load on the +5V rail grows up. Still, it remains within 3% at loads below 60 watts, which is going to be enough for any modern PC configuration.

It’s worse with the +3.3V voltage which deflects the most when there’s a low load on the +3.3 rail combined with a low load on the +12V rail, as is typical of an idle computer. That’s not going to be a big problem, though.

Output Voltage Ripple

The overall level of high-frequency pulsation isn’t high, but there are occasional spikes of voltage above the permissible limits. The oscillogram for the +12V rail shows that such spikes coincide with the switching of transistors. Voltage spikes of this kind aren't good, but can hardly interfere with the operation of your computer.

The same goes for the low-frequency voltage ripple except that the voltage spikes are not so regular.


The PSU is cooled by an ADDA AD1212HB-A71GL fan (the same as in the SS-620GM). It’s rated for 2200 RPM, which is a very high speed for a PSU that comes bundled with a silence-oriented system case.

About 40% of the fan is covered with a transparent plate to optimize air flows.

It’s good that the fan starts out at a speed of below 500 RPM and keeps it until a load of almost 200 watts. But then it accelerates to 1000 RPM at 300 watts and becomes downright noisy at 400 watts. The fan reaches its top speed of over 2000 RPM at about 430 watts. It maintains the same speed afterwards and is surely not comfortable then.

Take note that the fan speed increases at a faster rate than the temperature inside the PSU: the difference in temperature between the incoming and outgoing air is constantly diminishing, which is indicative of a suboptimal fan regulation algorithm.

The aerodynamic noise of the fan’s impeller was accompanied with some mechanical sounds. This must be a defect of the particular sample of the fan because ADDA products are usually free from such problems.

All in all, the Antec Neo ECO 620C, just like its Seasonic progenitors, is almost silent at low loads but becomes average in noisiness at a load of 300 watts. At a load of 400 watts its noise is already uncomfortable.

Efficiency and Power Factor

The power factor notches 90% at a load of 70 watts, reaching 99.7% at the peak. That's an excellent result.

The PSU is over 82% efficient through most of the load range, which is somewhat lower than the efficiency of its Seasonic progenitor but sufficient for 80+Bronze certification (Antec didn’t take the trouble of getting it for some reason, limiting itself to the basic 80+ certification).

+5V Standby Source

The standby source is blameless. Its voltage deflects no more than 0.1 volts from the default level whereas the industry standard allows a 0.25-volt deflection.


The Antec Neo ECO 620C is in fact identical to the Seasonic S12-II Bronze with a rating of 620 watts. Compared to the latter, it has somewhat lower efficiency and stronger output voltage ripple but offers longer cables, particularly the mainboard's 4+4-pin one.

This model will not be quiet if you use your computer for anything harder than just web-browsing and movie-watching.

Enhance EPS-1280GB4 (800 W)

Unlike the Scythe Stronger, this Enhance PSU came to us under its real manufacturer’s name, but without packaging. It differs from the Enhance EPS-1280GA in exterior design and modular cables. Let’s see if there are any internal differences between them.

Exterior Design

The PSU is quite eye-catching:

It’s got a rough dark-gray coating, a translucent fan with blue highlighting, and a gold-colored grille with the manufacturer’s name. These small details endow it with individuality in contrast with most other PSUs selling today.

It doesn’t differ from other PSUs in anything substantial, though. It’s got a meshed back panel with a mains connector and On/Off switch while the rest of its panels are blank.

Circuit Design

Notwithstanding the outward difference, the interior of the EPS-1280GB4 is identical to that of the EPS-1280GA, except for the card with connectors for detachable cables.

The PSU features active PFC and dedicated voltage regulation based on magnetic amplifiers.

There are high-quality Teapo capacitors rated for an operating temperature up to 105°C at the PSU’s output.

The “barrels” at the input are rated for 85°C, but this part of the case has better thermal conditions.

Cables and Connectors

The Enhance EPS-1280GB4 (800 W) is equipped with the following cables and connectors:

The cables are long enough even for system cases with a bottom PSU bay and a dedicated cable compartment. Flat and very flexible, they are also easier to deal with than traditional nylon-sleeved ones.


The specifications are identical to those of the Enhance EPS-1280GA and up to today’s standards. The PSU can deliver 780 out of its full 800 watts across the +12V rail.

Among the +12V lines the V3 and V4 ones have the highest load capacity as they are meant for graphics cards. Even if you connect two 8-pin graphics card connectors to one of these lines, the combined load won't exceed 25 amperes whereas the allowable maximum is 28 amperes.

Temperature and Noise

Besides the exterior design and modular cables, the cooling system is yet another difference of this model from the Enhance EPS-1280GA.

The previous model used to be cooled by a standard 120mm fan whereas the Enhance EPS-1280GB4 features a 135mm DFB132512 fan from Young Lin Tech.

The EPS-1280GA pleased us with its quietness in our earlier tests but the EPS-1280GB4 is even better! The fan speed remains constant at 800-850 RPM up to a load of 600 watts. After that the fan accelerates in a linear manner, crossing the subjectively comfortable level of 1000 RPM at 750 watts. The speed is only 1150 RPM at full load.

There is no danger of overheat because the difference in temperature between the incoming and outgoing air is 12°C. That’s quite acceptable.

UPS Compatibility

Connected to my APC SmartUPS SC 620, this PSU was stable at loads up to 386 and 280 watts when powered from the mains and batteries, respectively.

Output Voltage Stability

The PSU featuring dedicated voltage regulation (even though not based on the newfangled DC-DC converters), we can expect it to be very good in this test.

The +12V voltage fluctuates within 3% from the default level, preferring high loads: the higher the load on the +12V rail, the closer this voltage is to its nominal value. It is within 2% at loads above 250 watts and within 1% at loads above 400 watts.

The +5V and 3.3V voltages are within 2% of the default levels at typical loads, so this PSU delivers stable voltages indeed.

Output Voltage Ripple

The high-frequency output voltage ripple is within the norm.

The same goes for the low-frequency ripple.

Efficiency and Power Factor

The power factor is just what you can expect from a PSU with active PFC.

The EPS-1280GB4 is over 85% efficient at loads of 20 to 100%. This is a very good result, although its non-modular cousin did somewhat better in this test.

+5V Standby Source

The standby source is okay, but its voltage drop at high load is higher than with the EPS-1280GA.


Just like the earlier-tested Enhance EPS-1280GA, the EPS-1280GB4 is very good electrically. Moreover, it has become quieter and features handy detachable cables. This PSU is going to be a perfect choice for users who want their computer to be quiet even at high loads.

Hiper K800

The second Hiper product in this review comes from the senior K series and is in fact the first original model in it because the K700 model is based on the M700 that has a simpler circuit design and is similar to the above-discussed M600. The only difference of the K700 from the M700 is its modular design and K series packaging.

As opposed to the plain cardboard packaging of Hiper’s less advanced products, the K series comes in a plastic box that you may find handy for storing tools or something. The accessories are the same as those included with the M600: two sets of crews (ordinary and thumbscrews), a pack of cable straps, and a user manual. There are also detachable cables in the box.

Exterior Design

The K800 has a rather standard appearance and differs from the above-discussed M600 in nuances only.

You can see connectors for detachable cables and vent grids in the side panels. The fan's impeller is painted silvery; the fan is highlighted in blue.

The On/Off switch has become larger and is located next to the mains connector.

Circuit Design

Like the first product from Hiper in this review, the K800 is based on Andyson's Performance platform, but this time around it's the more advanced E series.

It’s easy to see that the PCB is larger and has higher component density.

This PSU features dedicated voltage regulation based on DC-DC converters soldered on two individual cards above the +12V choke.

The PSU uses Teapo capacitors everywhere, including its output. Like the previous PSUs, this is has active PFC.

Thus, the Hiper K800 is the most up-to-date product among the tested six in terms of technologies, but let’s see how well those technologies are implemented in it.

Cables and Connectors

The K800 is equipped with the following cables and connectors:

The cables aren’t very long. The mainboard’s 4+4-pin cable is going to be too short to be hidden behind the mainboard’s mounting plate in a system case with a bottom PSU bay. It’s impossible to plug a peripheral power cable into a graphics card cable’s connector by mistake because the keys differ.


Like the Hiper M600, the K800 has a rather low load capacity of the +12V rail: only 648 out of its full 800 watts (i.e. 81%).

The combined load on the +12V, +5V and +3.3V rails must not be higher than 779 watts; the remaining 21 watts refer to the -12V line and the +5V standby source.

The PSU can cope with a short-term load of 850 watts.

Temperature and Noise

The Hiper K800 is cooled by the same fan as we’ve seen in the Hiper M600 above, except for colors. The fan itself is now silvery and its highlighting is blue rather than red.

The K800 has no overheat problems. The outgoing air is almost as cold as the incoming one even at maximum load but what's the tradeoff?

The fan accelerates quickly as soon as you turn the computer on. Starting up from 1000 RPM at a load of 50 watts, the fan hits its top speed of 1800 RPM at 300 watts and keeps it until the full load of 800 watts.

With this fan regulation, the PSU is merciless to its user in terms of acoustic comfort.

UPS Compatibility

Connected to my APC SmartUPS SC 620, this PSU was stable at loads up to 365 watts when powered by the mains but couldn’t switch to the UPS batteries even when the load was as low as 280 watts.

Output Voltage Stability

A PSU with dedicated voltage regulation can be expected to deliver stable voltages at any load.

Indeed, the voltage on the +12V rail always remains within 3% of the default level and even fits within 1% at loads of 250 watts and higher.

There are no problems with the +5V rail, either. This voltage is going to deflect no more than by 2% in the typical load range.

The +3.3V rail is somewhat worse. This voltage deflects by 4-5% when there is a low load on it as well as on the +12V rail, which is typical of a modern computer in idle mode. This shouldn’t be a problem for a top-end configuration that needs a considerable amount of power even when idle, but an energy-efficient computer’s HDDs may get finicky about such deflections in idle mode, even though the voltage does remain within the standard-defined limits.

Output Voltage Ripple

The output voltage ripple on the +12V and +5V rails is conspicuous, yet much lower than the permissible limits.

The voltage ripple is also low at the double frequency of the mains.

Efficiency and Power Factor

The power factor is just what you can expect from a PSU with active PFC whereas the efficiency is inferior to that of Hiper's junior model.

Although Andyson Performance E series PSUs are 80+Bronze certified, the Hiper K800 wouldn't be able to claim that certification. At 20% load, its efficiency is 0.1% lower than the requirements for 220V mains (80.9% efficiency). At 50% load, its efficiency falls 0.5% short of the 80+ requirements (84.5%). The PSU is 83-84% efficient in the typical load range, but can never hit 85%.

On the other hand, Hiper doesn't certify this PSU for 80+ and its efficiency is indeed “higher than 80%” as promised by the maker. So, there is no misleading the customer here.

+5V Standby Source

The standby source is okay.


Alas, the Hiper K800 falls short of my expectations, despite its advanced circuit design. Its efficiency is rather low and its +3.3V voltage fluctuates too much (even though within the standard-defined limits). That's not what one wants from a modern PSU that claims to be a high-quality product. Like the M600, the Hiper K800 has a rather low max load on the +12V rail, too.

Well, these downsides could be put up with if it were not for its noisiness. The fan regulation algorithm is downright inadequate. The fan begins to accelerate linearly right after you turn your computer on and reaches its maximum speed at a load of only 300 watts.

Hopefully, this only refers to this model because I haven’t heard any noise-related complaints regarding the Hiper K1000.

Scythe Chouriki 2 Plug-in (SPCR2-850P)

Fortunately, the second PSU from Scythe hasn’t become outdated by the time I got to tetsing it. It is currently the only current PSU that Scythe offers in the European market.

This PSU comes in a matte dark-gray cardboard box covered with descriptions of its various features in several languages.

Exterior Design

The PSU case is unpainted steel of a dark hue. It has a rough surface.

The metal is smooth in the punched-out grooves for the vent grid, in contrast with the ostensible roughness of the other surfaces. There is a stylized Scythe logo on the grid.

The back panel grid has an unusual shape of the openings. Otherwise, the exterior design is ordinary.

Circuit Design

There's nothing extraordinary about this PSU’s circuitry, either, yet it has everything necessary for a high-wattage product from a respectable brand: dedicated voltage regulation based on magnetic amplifiers and active power factor correction.

The internal component density is rather high; the quality of assembly and soldering is blameless.

The UL code on the PCB suggests that the PSU is manufactured by Yi Li An Electronics (Shenzhen) Co. Ltd, but I couldn't find any detailed info about it.

The PSU has KZE series capacitors from United Chemi-Con at the output. They enjoy an excellent reputation.

Cables and Connectors

The Chouriki 2 Plug-in is equipped with the following cables and connectors:

Just like the Stronger 600 W Plug-in, this model prevents the user from connecting cables incorrectly but the main cables are rather too short.

There are stickers with the PSU’s model name on the detachable cables. This may be helpful for owners of multiple computers with a different modular PSU in each.


The specs are attractive. The PSU can yield all of its 850 watts across the +12V rail and sports 80+Silver certification (this should ensure efficiency of 85% and higher at loads of 20 to 100% and efficiency of 89% and higher at 50% load).

Temperature and Noise

The PSU is cooled by a 135mm 9-blade Scythe Kama Flex fan that runs on fluid dynamic bearing (part number: SA1325FDB12PM). About a quarter of the fan’s area is blocked by a triangular sheet of transparent plastic to optimize air flows.

The fan starts out at about 600 RPM and keeps this speed until a load of 160 watts. It remains quiet until a load of 450 watts when it reaches a speed of 1000 RPM. The fan accelerates afterwards in the same steady manner, reaching 1600 RPM at full load. This is a lower speed than with many other same-wattage PSUs. The difference in temperature between the incoming and outgoing air is 11°C, which is far from dangerous.

Overall, the Chouriki 2 Plug-in is above average in terms of noisiness. I guess there will be even noisier sound sources, like a graphics card cooler, in those situations when its fan becomes audible.

UPS Compatibility

Connected to my APC SmartUPS SC 620, the PSU was stable at loads up to 390 watts when powered by the mains but couldn’t switch to the batteries even at 280 watts.

Output Voltage Stability

The +12V rail behaves like in the Hiper K800 and Enhance EPS-1280GB4: this voltage deflects less from the nominal value when the load is higher. However, the Chouriki 2 Plug-in allows this voltage to deflect more (up to 4% at minimum loads and with a large 3% zone) and only keeps it within 1% at loads over 500 watts on the +12V rail.

The green zone of the +5V voltage is somewhat higher than the typical load range, yet it's not going to deflect more than 2% from 5 volts in most real-life computers.

The +3.3V voltage is most stable when there’s medium load on the +12V rail. It doesn’t deflect more than by 3% at low and high loads on the +12V rail, though.

Overall, this PSU does well at rather high loads. It’s going to be good at powering a gaming rig with a couple of SLI or CrossFire-linked graphics cards.

Output Voltage Ripple

The high-voltage ripple is conspicuous at full load but doesn't go beyond the prescribed limits.

The same goes for the low-frequency ripple.

Efficiency and Power Factor

The power factor is somewhat lower than what you can get with the best active PFC implementations but that's not a crucial parameter for home users.

The efficiency meets the 80+Silver requirements: 88.9% at 20% load, 91.1% at 50% load, and 87.3% at full load.

+5V Standby Source

The load of 6 amperes, which is very high for a standby source, is handled without problems.


The Scythe Chouriki 2 Plug-in (SPCR2-850P) is good in terms of electric properties, highly efficient, not very noisy and free from obvious shortcomings. It shouldn’t be installed into low-end computers as its purpose is to power top-performance gaming machines.


It is the Enhance EPS-1280GB4 model that stands out among the tested six. It’s got an eye-catching design, works very quietly throughout the entire load range, and offers sufficiently long and flexible detachable cables - everything for the user to feel comfortable with it. Although its electric properties are somewhat inferior to its cousin with fixed cables, the EPS-1280GB4 is superior to it in every other aspect.

The Scythe Chouriki 2 Plug-in features higher wattage and excellent efficiency combined with low noise at low and medium loads. Its voltages are not ideally stable at low loads, though. A high-end PSU can be expected to do better in this respect.

The Hiper PSUs proved to be rather weak in terms of their +12V load capacity. Their wattage ratings are overstated by a hundred watts. Besides, the K800 model has a terrible fan regulation algorithm which leads to a fan speed of 1800 RPM at a load of only 300 watts. On the other hand, the M600 won’t be a bad choice for a midrange PC thanks to its quiet operation and rich selection of connectors.

The Antec PSU that I took from a Sonata IV system case is just an average product without serious defects. It is noisy at above-average loads, though.

As for the Scythe Stronger 600 W Plug-in, I can understand why it has already been discontinued. Its cross-load characteristics are very poor.