400-520W Power Supply Units Roundup

Not every user out there needs a power supply unit capable of handling an overclocked system with a pair of high-end graphics cards inside. A mainstream system will be OK with a 400-500 W PSU, if it is designed correctly and is of quality manufacture. Today we are going to discuss several products like this.

by Dmitry Vasiliev
12/16/2011 | 05:34 AM

It goes without saying that the overwhelming majority of computers working in our homes and offices are far from top-end. They are average in performance and do not need high-wattage power supply units. A 400 or 500-watt PSU is going to be just enough. It’s about such PSUs that we’ll be talking in this review. Not all of them are hot-new, yet they are all available in shops and so deserve taking a look at.

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

Cooler Master Elite Power RS-400-PSAP-J3

Cooler Master offers various kinds of PSUs. Notwithstanding the boastful name, the Elite Power series this model belongs to is actually at the very bottom of the company’s product range.

The PSU is shipped in a uniform Elite Power box. The wattage rating of the specific model is indicated by a sticker on the front side.

On the back of the box you can find a table listing power connectors the different Elite Power series models offer.

Exterior Design

We can’t expect anything extraordinary in terms of exterior design from an entry-level PSU.

Indeed, the Elite Power RS-400-PSAP-J3 has an unassuming appearance.

It’s got an unpainted steel case, a 120mm fan placed closer to one side, and small vent slits in the panel with power cables.

Circuit Design

It’s easy to identify the real maker of the PSU. There is a FSP logo on the daughter card.

FSP is a respectable maker, but the circuitry of this PSU is outdated. The PCB and the overall design are almost identical to those of FSP’s 60PN(PF) and 60THN-P series units we tested as far back as 2005.

The difference from the mentioned oldies boils down to the controller cards and the shape of the heatsinks. This platform used to be successful in its time and is still used by FSP in entry-level PSUs.

As the consequence of the respectable age of the platform, the Elite Power RS-400-PSAP-J3 has neither dedicated voltage regulation nor active power factor correction. Its efficiency isn’t likely to be high, either.

There are high-quality Teapo capacitors at the output. The OST capacitors installed at the PSU’s input are somewhat lower quality.

Cables and Connectors

The Elite Power RS-400-PSAP-J3 is equipped with the following cables and connectors:

The cables are all fixed and have no sleeves. There is a plastic strap on each stretch of each cable (in between connectors), so you can lay them out more or less neatly. The mainboard cable may prove to be too short for a system case with a bottom PSU bay.


The text on the PSU label can shock anyone. We can read the pretty round number “400 watts” on the product box, but the small letters on the label tell us that the total load on the +3.3V, +5V and +12V rails must not exceed 327.9 watts! We can’t get as high as 350 watts even if we add the maximum load on the auxiliary lines (-12V and standby voltage). We must confess we hadn’t expected such a blatant lie to the customer in a product that comes under the respectable Cooler Master brand.

The PSU can yield 276 watts across the +12V rail, which is not much by today’s standards, even if we take 327.9 rather than 400 watts as the PSU’s full output power. The load capacity of 120 watts is quite sufficient for the +3.3V and +5V lines.

The specifications suggest that this product is based on the FSP ATX-350N model with the addition of more power connectors and the label that promises extra 50 watts which the PSU can’t actually deliver.

UPS Compatibility

The PSU was stable with my APC SmartUPS SC 620 at loads up to 285 watts irrespective of whether powered by the mains or the UPS’s batteries.

Cross-Load Stability

The +12V voltage sags when the other rails are under load, but is stable enough in the typical load range.

The +5V voltage is even more stable. It only goes far from the required level when the load is very high or very low.

The +3.3V voltage is the most stable of all.

It must be noted that this PSU can only power up the weakest of our reference PC configurations but the voltages would all be very stable (within 1% of the required levels) with that configuration at full load.

Output Voltage Ripple

The Elite Power RS-400-PSAP-J3 meets the requirements in terms of output voltage ripple. The high-frequency ripple is conspicuous on the +12V rail, less conspicuous on the +3.3V rail and almost invisible on the +5V rail.

The +12V rail is also the noisiest at the double frequency of the power mains. The +3.3V rail is the most stable here. The output voltage ripple is within the norm on each rail, though.

Temperature and Noise

The PSU is cooled by a 7-blade 120mm Yate Loon fan (D12SM-12) that has a rated speed of 1650 RPM.

The fan starts out at about 1300 RPM, which is not quiet. On the other hand, it doesn’t accelerate much at higher loads, never reaching even 1400 RPM.

Efficiency and Power Factor

Cooler Master’s PSU is somewhat more efficient than FSP’s 60PN(PF) and 60THN-P series products and is comparable to FSP’s later Optima series which is based on the same platform. It is 80% efficient at the maximum, which isn’t high by today’s standards. Its power factor is typical of passive PFC: about 80% at low loads and somewhat lower at high loads.

Standby Source

The standby voltage is very stable, fluctuating by no more than 1%.


If you need to power an entry-level PC and do not care about noise, Cooler Master’s Elite Power RS-400-PSAP-J3 is going to be a good choice. On the other hand, if you don’t mind using power adapters, you can prefer the original FSP ATX-350N and have the same specs (except for fewer connectors) for less money. Even the higher-wattage FSP ATX-450N costs less than this Cooler Master (yet the latter has more connectors anyway).

Enhance ATX-0240GA

This PSU is the only one in this review to sell under its real manufacturer’s brand. Let’s see how good Enhance’s entry-level products are.

Exterior Design

The ATX-0240GA looks simple and cheap with its punched-out fan grid and rather thin panels.

There are no other vents save for the fan grid and the honeycomb mesh in the back panel.

The PSU is painted a smooth matte paint which seems to be the only original nuance in its appearance.

Circuit Design

The ATX-0240GA is more advanced than the above-discussed Cooler Master in its interior design.

Of course, it’s hard to expect such advanced technologies as dedicated voltage regulation from an inexpensive product, but at least it’s got active power factor correction.

The component density isn’t high below the characteristic fingered heatsinks.

Like the Cooler Master, the ATX-0240GA has Teapo capacitors at the output. It also has Teapo capacitors at the input (these are rated for 85 rather than 105°C).

Cables and Connectors

The Enhance ATX-0240GA is equipped with the following cables and connectors:

The mainboard and graphics card cables are sleeved. The rest of the cables have four plastic straps on the stretch between the PSU and the first connector. It’s only thanks to the straps that the cables hold together and are just as good as the sleeved ones except for their looks.

The cables are longer than usual, yet I wish the mainboard cable were some 5 centimeters longer yet. This extra length can make a difference in system cases with a bottom PSU bay which are so popular nowadays.

The number of connectors is unexpectedly high for a PSU of that wattage and should be enough for any configuration the ATX-0240GA can power up. However, I tested a presale version of the PSU. The retail version has one PATA or SATA connector less on each cable. This should also be enough, though.


The ATX-0240GA specs aren’t impressive but true. The PSU can yield up to 300 out of its full 400 watts across the two +12V lines, which is only 75%. The load capacity of the +5V and +3.3V rails is an adequate 120 watts. My presale ATX-0240GA lacked an 80+Bronze badge but its retail version has such certification.

UPS Compatibility

The PSU was stable with my APC SmartUPS SC 620 at loads up to 355 watts when powered by the mains but could only switch to the UPS’s batteries at 300 watts.

Cross-Load Stability

The +12V rail is more stable than that of the Cooler Master. It is only at minimum load or when the load is misbalanced towards the +3.3V and +5V rails that the +12V voltage deflects more than by 3% from the required level.

As for the rest of the voltages, the ATX-0240GA is similar to the Cooler Master in this test.

The +5V voltage sags when there’s high load on the +12V rail or on the +5V rail. On the other hand, this voltage isn’t going to deflect more than by 2 or 3% under typical loads.

The +3.3V voltage is close to perfect, always staying within 2% of the required level.

Like the Cooler Master above, the ATX-0240GA can only power up the weakest of our three reference configurations, but its voltages would be within 1% of their nominal values with that configuration.

Output Voltage Ripple

The high-frequency ripple is close to but never exceeds the permissible limits.

The low-frequency ripple is weaker, the permissible limits being only approached by occasional voltage spikes.

Temperature and Noise

The PSU is cooled by a 7-blade 120mm ADDA fan (AD1212HS-A71GL) with a rated speed of 2200 RPM.

The fan starts out at about 900 RPM and doesn’t accelerate much until a load of 250 watts. Then the speed increases linearly, reaching 1100 RPM at full load.

The PSU is rather quiet and its fan regulation algorithm is praiseworthy.

Efficiency and Power Factor

The maximum efficiency of the Cooler Master was 80% but the Enhance ATX-0240GA beats that even at 50 watts. Overall, the ATX-0240GA meets the 80+Bronze requirements. That’s quite an achievement for an inexpensive PSU.

It’s no wonder that the Enhance ATX-0240GA is colder than the Cooler Master RS-400 notwithstanding its higher effective wattage and lower fan speed. It just dissipates less power as heat.

The power factor is high, just as you can expect from a PSU with active power factor correction.

Standby Source

The standby source copes just fine.


The Enhance ATX-0240GA is an affordable PSU with excellent functionality and efficiency (for its class). It is also quiet. A good choice for a modest PC configuration for reasonable money.

Antec VP450P

This model comes from Antec’s junior PSU series targeted at office machines or entry-level gaming PCs. It has already been replaced with the VP450 model (without the P suffix) but you can still find it in shops.

The VP450P comes in a small glossy cardboard box.

Exterior Design

The VP450P looks exactly like any other same-class model except for the black paint (entry-level PSUs often come unpainted).

Its case has a reduced length. The 12cm fan is covered with a wire grille. We’ll see a lot of such PSUs yet.

There are a few small vent grids in the panel with cables. The rest of the panels are blank.

Circuit Design

The real manufacturer of this product is FSP. You can see its marking on some components.

There’s nothing extraordinary inside: just an ordinary PSU with active PFC and without dedicated voltage regulation.

The small heatsinks are intricately shaped.

There is a Weltrend WT7527 chip next to the mains connector. It protects the PSU against overload, short circuit and other problems of this kind.

There are electrolytic capacitors from CapXon on the PSU’s output as well as elsewhere. These are rather good components from Taiwan.

Cables and Connectors

The Antec VP450P is equipped with the following cables and connectors:

Like with many other PSUs of this class, the mainboard power cable is sleeved, but the others are just strapped together.

Despite the straps, the cables stick out because the wires vary in length within a single cable. The other PSUs are not free from that problem, either, but it’s rather too conspicuous here.

The cables aren’t very long. You may have to lay the mainboard cable out through the main interior of your chassis rather than through a cable compartment if you’ve got a system case with a bottom PSU bay.

It’s good that there is a dedicated cable with a single SATA connector, yet it is going to be too short to reach from a bottom-bay PSU to the optical drive bay.


The specifications are typical enough for an entry-level product. The PSU can give you 360 out of its full 450 watts across the two +12V lines. The combined load capacity of the +3.3V and +5V rails is 120 watts.

The max load on the +5V rail is unexpectedly low at 15 amperes. Although it’s more than enough for modern PCs, this rail usually has a higher load capacity.

UPS Compatibility

The PSU was stable with my APC SmartUPS SC 620 at loads up to 395 watts when powered by the mains but could only switch to the UPS’s battery at loads up to 285 watts.

Cross-Load Stability

We’ve got a characteristic picture with the +12V voltage: it is stable within the load range typical of modern PCs but fluctuates when there’s very high or low load on the +3.3V and +5V rails.

I’ve mentioned the suspiciously low load capacity of the +5V rail above and indeed this voltage is very unstable. It deflects by 5% from the default level even at 40-50 watts. Both of our reference configurations this PSU is able to power up are in the 4% zone.

The +3.3V voltage isn’t perfect, either, but deflects no more than by 3% in the typical load range.

By the way, the PSU could only yield about 80 watts instead of the specified 120 watts across the +3.3V and +5V rails combined without violating the voltage stability requirements.

Overall, this performance is satisfactory, but you can find PSUs with more stable voltages in the same product category.

Output Voltage Ripple

The high-frequency ripple is close to the permissible limits on the +12V rail. The +3.3V and +5V rails are more stable, but there are occasional voltage spike up to the limits described by the industry standard.

The same goes for the low-frequency ripple. The +5V voltage is the most stable one, lacking any voltage spikes.

Temperature and Noise


The PSU is cooled by a Yate Loon fan (D12SM-12) that has a rated speed of 1650 RPM. We’ve seen the same fan in the Cooler Master RS-400.

The start speed is lower at 1000 RPM than that of the Cooler Master but the fan accelerates linearly right from the start, reaching 1500 RPM at a load of 350 watts. The fan doesn’t speed up much after that, keeping the difference in temperature between the incoming and outgoing air low at 7°C.

The PSU isn’t silent, yet not uncomfortable.

Efficiency and Power Factor

Although the Antec lacks even basic 80+ certification, its specs are close to meeting the Bronze version of that standard. It is over 85% efficient at loads of 80 to 310 watts and about 82% efficient at full load.

The power factor is lower than usual for active PFC, but that’s unimportant for home users.

Standby Source

The standby source copes with its job well, keeping its voltage within 2% of the required level.


Being rather efficient, the Antec VP450P has problems with the +5V rail and isn’t very quiet. Its price seems to be too high. The higher-wattage and more advanced Antec HCG-520 is but slightly more expensive yet superior in every parameter whereas competitors’ products of comparable wattage and efficiency are cheaper and free from the mentioned downsides. 

Thermaltake Litepower LP-450AH2NF (W0293RU)

Thermaltake’s Litepower series includes inexpensive PSUs of average wattage.

The 450W model comes in a medium-sized box made of matte cardboard.

The text on the back of the box informs you that there is indeed a PSU inside. You can also see a table listing connectors the different Litepower series models are equipped with.

Exterior Design

Save for the stickers and color, the PSU looks exactly like most of the other products in this review. Its 120mm fan is shifted towards one side, too.

There are vent holes in the panel with cables.

Circuit Design

The UL certificate number (E190414) refers to FSP and the internal design of this model is in many points similar to the above-discussed Antec VP450P, also manufactured by FSP.

In fact, the Litepower LP-450AH2NF only differs from the Antec VP450P in some minor details like the component layout in the middle of the case, the smaller central heatsink, and the different brand of the capacitors.

Thermaltake employs Teapo capacitors which enjoy a better reputation than the CapXon capacitors of the Antec PSU.

Otherwise, this model is exactly like others of its class, featuring active PFC and lacking dedicated voltage regulation.

Cables and Connectors

The Litepower LP-450AH2NF is equipped with the following cables and connectors:

The mainboard’s 20+4-pin cable is the only one to be sleeved. The rest of the cables have one strap until the first connector. There is another strap between the connectors on the PATA power cables.

The cables aren’t long enough to connect to a PSU in a bottom bay unless you use an extension cable for the mainboard.

It’s also not good that the available SATA power connectors all share the same cable. You will hardly be able to connect more than a couple devices if one of them is an optical drive. It would be better to have more SATA instead of PATA power connectors, especially as the latter are mostly used in modern PCs for powering fans.


Despite the overall similarity to the Antec VP450P, the Litepower LP-450AH2NF has more impressive specs. It can give you up to 408 watts (or 90% of its full power) across the two +12V lines. The +5V line has a higher load capacity, too, as it can give you up to 120 watts (24 amperes) out of 123 watts, which is the combined load capacity of the +5V and +3.3V lines.

As opposed to the Antec, the Litepower LP-450AH2NF features official 80+Bronze certification.

UPS Compatibility

The PSU was stable with my APC SmartUPS SC 620 at loads up to 357 watts when powered by the mains. They switched to the UPS’s batteries normally at loads up to 325 watts.

Cross-Load Stability

Unless there is a very low load on the +12V rail, its voltage remains within 3% of the default level. The difference is even as small as 1% in the typical load range. That’s a splendid result.

The +5V voltage is blameless, too. It’s only at highly misbalanced loads that it deflects much from the required level. It won’t differ from 5 volts sharp by more than 2% in the typical load range. The green zone of this voltage is somewhat higher than our reference configurations, though.

The +3V rail is stable enough, too. This voltage deflects no more than by 3%.

Output Voltage Ripple

The output voltage ripple is strong on the +12V and +3.3V rails, reaching up to the permissible maximum on the latter. The +5V rail is much better in this respect.

The picture doesn’t change at the double frequency of the power mains. The voltage ripple is strong on the +3.3V rail and weak on the +5V rail.

Temperature and Noise

The Litepower LP-450AH2NF is cooled by a 120mm fan that has a Thermaltake label (the part number is TT-1225A) but the real manufacturer Yate Loon is indicated, too. The blades of this fan are somewhat wider than usual at the ends.

The fan starts out at 950 RPM and keeps this speed until 50% load, being quite comfortable. Then it begins to accelerate linearly, reaching 1600 RPM at 100% load. The fan gets uncomfortably noisy at near-maximum loads.

Overall, this PSU is quite acceptable in terms of noisiness.

Efficiency and Power Factor

According to my measurements, the Litepower LP-450AH2NF is somewhat less efficient than its relation Antec VP450P at low loads but more efficient at high loads: over 85% at 130 watts and higher.

The active PFC device isn’t very good here. It’s about as effective as that of the Antec VP450P.

Standby Source

The standby source is blameless, keeping its voltage within 2% of the required level.


The Thermaltake Litepower LP-450AH2NF is good in electrical and acoustic characteristics, but you may find its cables not very handy. You may have to use a power adapter for your optical drive and prefer a system case with a top PSU bay. But if its cables suit you just fine, it can make a good buy for reasonable money.

ExeGate ATX-500PPX

This section of my review is going to be short. After a long period of testing without any casualties, the ExeGate ATX-500PPX has joined our collection of dead PSUs. I had recorded its cross-load specs and almost finished testing its fan (the fan speed test is quite long and can be considered a test of the PSU's ability to work continuously under high load), but about 100 seconds into the test I heard a loud clap with all the consequences that might be expected. Well, I had been given a clue about this outcome as the PSU had smelled suspiciously after reaching a load of 400 watts.

Exterior Design

Tightly wrapped into transparent plastic, this PSU comes without any accessories like a user manual or fasteners.

The exterior design looks familiar already: compact dimensions and a 120mm fan shifted towards one side. The only new feature we can see here is that the back vent grid has a square rather than honeycomb mesh.

Also on the back panel you can see a mains connector, an On/Off switch, and a passive PFC choke fastened with screws.

Circuit Design

The interior of the ExeGate ATX-500PPX doesn’t provoke any apprehensions.

Everything is neat and tidy. There is no sign of the manufacturer having tried to use as cheap components as possible.

The only suspicious thing is that the capacitors are made by an obscure firm BH. I could only find one reseller of such capacitors but not their actual manufacturer on the Web. They were not the reason for the death of the PSU, though.

The ExeGate ATX-500PPX can match the Cooler Master model in ancestry. Its circuit design looks like the ancient InWin IW-ISP300A3-1. It’s even got the same PWM controller chip – SG6105 (but the chip is ADZ rather than D modification). The component layout is almost identical.

You can find the name of the PCB maker next to the fuse, beneath the passive PFC choke. As a matter of fact, Foshan Shunde City XinHuiDa Electronic Co., Ltd. even offers 80+Gold products in its EPS (12V2.92) series, but the ExeGate ATX-500PPX is not one of them. It is based on a simple 400-watt XHD-400T model from the ATX 2.3 series which has both of its two distinguishing features: the passive PFC choke screwed to the back panel and the square-shaped vent holes. The electrical specs of the XHD-400T are close to those of the ExeGate ATX-500PPX, too.


The max output power of 500 watts is quite a lot, but the PSU can only yield 370 watts (only 74% of the total) across the +12V rail. The load capacity of the +3.3V and +5V rails combined is 130 watts, which is more than necessary in real life and seems to be higher than the PSU’s real capabilities (the original manufacturer’s 400- and 500-watt PSUs promise only 120 watts on those two rails combined).

Interestingly, the mean time between failures for this PSU series is specified to be only 10 thousand hours at the ExeGate website. This is only one tenth of what most other PSU makers promise, including the original XinHuiDa products. This may be just a typo, but I hope that ExeGate is objective in estimating the perspectives of a Chinese 400-watt PSU rebranded as a 500-watt unit with a peak output power of 550 watts and equipped with capacitors from an obscure firm.

Cross-Load Stability

The +12V and +5V rails deflect by 3% within the typical load range, which is acceptable for an inexpensive PSU. They deflect the most when there is a very high or a very low load on the +5V and +3.3V rails.

The +3.3V voltage is even more stable. It deflects by 3% only when there is high load on both the +3.3V and +12V rails concurrently.

Temperature and Noise

The ExeGate ATX-500PPX is cooled by a 120mm fan from BaoDiKai (the part number is BDM12025S). More than one third of the fan is covered with a piece of plastic. The part number corresponds to a 2000RPM model at the manufacturer's website but that model has a current of 0.23 amperes whereas this one, 0.15 amperes.

The fan doesn’t cope. It accelerates right from the start (an audible 1300 RPM even at minimum load) but then works at 1400 RPM or somewhat higher, allowing the temperature to rise up.

The natural outcome was the clapping sound of the PSU's suicide.


Perhaps somewhat paradoxically, I wasn't displeased with the ExeGate ATX-500PPX despite its failure during my tests. The problem is that the manufacturer put a wrong wattage rating on it. The PSU failed under continuous load but passed the cross-load test with short-term high loads.

On the other hand, even if ExeGate lowers the wattage rating to the realistic 400 watts, the ATX-500PPX can hardly make a worthy opponent to the far more efficient and quiet Enhance ATX-0240GA, for example, at its current price. So, the price should be lowered as well.

Antec High Current Gamer HCG-520

This PSU hails from Antec’s gamer-oriented High Current Gamer series. It’s a second model from below, after a 400-watt one.

The PSU comes in a rather large box that’s painted Antec’s traditional black and yellow. The classic color scheme is complemented with the red and white elements of the company’s gaming series.

Exterior Design

The HCG-520 is painted a rough matte-black paint with the red and white elements of the gaming series.

The exterior design is quite conventional. It’s a metallic box with blank panels except for the fan grid and the back mesh. The fan is placed in the center and its grid is shaped peculiarly like a square with rounded-off corners.

There are stickers with the manufacturer's name and PSU wattage on the sides of the case. There is also a table with the electric specs on one panel.

The overall appearance is nice, notwithstanding the lack of anything extraordinary.

Circuit Design

Antec does not develop PSUs, so let’s try to identify the real maker.

As opposed to the VP450P model manufactured by FSP, the HCG-520 is based on a Seasonic platform. The internal design, except for the color of the PCB and heatsinks, is identical to the 520-watt Seasonic S12-II Bronze.

I don’t think I should dwell on the familiar circuit design. I’ll just mention a few differences from the original product.

The daughter card near the mains connector is different. In the Antec PSU it has a PS223 chip which is responsible for voltage monitoring and overheat/overload protection.

An Infineon ICE1CS02 chip works as a PWM and PFC controller. Its daughter card is located in the opposite corner from the previous card, behind the input capacitor.

Like the original Seasonic, the Antec HCG-520 employs electrolytic capacitors from Nippon Chemi-Con (also known as United Chemi-Con) which enjoy a very good reputation. You can see KZE series capacitors at the output.

Cables and Connectors

The Antec HCG-520 is equipped with the following cables and connectors:

As opposed to the original Seasonic, the cables are sufficiently long. The HCG-520 is also better than the previous models in this review in offering a good selection of connectors and having all of its cables sleeved.

The higher level of quality of this product is indicated by the availability of two graphics card connectors. This PSU is obviously meant to power not just office machines. It's not without reason that it's got the word Gamer in its model name.


The PSU specifications coincide with those of the same-wattage Seasonic S12-II Bronze unit and are up to today’s requirements. You can get 480 watts (92.3%) out of the full 520 watts across the +12V rail.

By the way, it is the only PSU in this review to be able to power each of our three reference configurations.

UPS Compatibility

The PSU was stable with my APC SmartUPS SC 620 at loads up to 365 watts when powered by the mains, but could only switch to the UPS batteries at 280 watts.

Cross-Load Stability

The +12V voltage has a large 5% zone, but this deflection can only be observed when there’s an unrealistically high load on the +5V and +3.3V rails. This voltage isn’t going to differ from the required level more than by 2 or 3% at typical loads.

The +5V voltage deflects from the default level when there is a very high load on the +5V rail or a very low load on the +12V rail. Anyway, each of our three reference configurations is in the 1% zone.

The +3.3V voltage seems to be the most stable as it deflects no more than by 3%, but the 1% zone doesn’t cover the weakest of our reference configurations.

So, the output voltages of the Antec HCG-520 are quite satisfactory.

Output Voltage Ripple

The high-frequency voltage ripple isn’t strong but there are spikes above the permissible limits on each power rail. Such spikes are regular on the +12V rail (at the moments of switching of the transistors) and occasional on the other rails.

The low-frequency ripple has fewer spikes. Moreover, the voltage spikes on the +3.3V rail do not violate the permissible limits.

Temperature and Noise

Like the original Seasonic, the Antec HCG-520 is cooled by an ADDA fan, but it’s the ADN512MB-A90 model now with more blades (11 instead of 7) and a larger diameter (135 instead of 120 millimeters).

The fan behaves like in the original Seasonic. Its speed is very low at loads up to 200 watts and then it suddenly accelerates to its maximum of 1900 RPM.

So, the PSU is almost silent at loads up to 200 watts, comfortable at loads up to 300 watts, and audible thereafter.

The Antec HCG-520 is overall comparable to the original Seasonic in terms of noisiness. The Antec has a lower maximum level of noise but gets noisy somewhat faster than the Seasonic.

Efficiency and Power Factor

The Antec HCG-520 is almost as efficient as the original Seasonic: close to 80% at 50 watts and over 85% at loads above 80 watts. That's an excellent result, so the PSU can proudly sport its 80+Bronze certification.

The power factor is high, just as you can expect from a modern PSU with active power factor correction.

Standby Source

The standby source doesn’t allow its voltage to deflect more than by 2%, the allowable deflection being 5%.


The Antec HCG-520 is similar to the Seasonic S12-II Bronze SS-520GB but has longer cables and a prettier exterior design. It may also turn out to be cheaper than the original Seasonic.


The PSUs have split up into three winners and three losers according to the results of my tests.

Of course, the first group is the most interesting one. It includes the Antec High Current Gamer HCG-520, Enhance ATX-0240GA and Thermaltake Litepower LP-450AH2NF.

The gamer-oriented PSU from Antec is going to be a good choice for a large system case with a bottom PSU bay, especially if you want to have a reserve of wattage for future upgrades. It is considerably more expensive than the other two leaders, though.

The Enhance ATX-0240GA is excellent in every parameter, including noisiness, and also comes at a lower price than the other two. So, if you don’t have plans on upgrading your system beyond its capabilities, it can make a perfect affordable PSU.

The PSU from Thermaltake takes an in-between position. It features good compatibility with UPSes but has short cables. Besides, the peripheral power connectors are not distributed among its cables in an optimal way. If you are sure that the cables and connectors won’t be a problem with your system case and PC configuration, you won’t be disappointed with it.

Now I want to add a few words about the less successful products.

The Antec VP450P is a real disappointment. Being highly efficient, this PSU has a very unstable +5V voltage, poor fan speed regulation (the fan accelerates linearly right from the start) and an undeservedly high price. It is only cheaper than the other Antec in this review, but the latter is free from the mentioned downsides and offers much more power on the +12V rail.

The Cooler Master can only be praised for its handy cables but there are too many shortcomings about it. Its real wattage is lower than the specified 400 watts. Its circuit design is outdated, its efficiency is low and the fan can be heard even at minimum load. This product is priced like the Enhance although the latter is superior in electrical and acoustic parameters, offers as many connectors and has longer cables.

The suicide from ExeGate is actually even better than the Cooler Master if you do not try to squeeze the specified 500 watts out of it. This wattage is as unrealistic as the Cooler Master’s 400 watts. Otherwise, it is cheaper than the Cooler Master RS-400, comparable to the latter in noisiness, has higher real wattage, and offers a better selection of cables and connectors. On the other hand, this PSU is uncompetitive against the products from Enhance and Thermaltake in terms of price/quality.