ATX Power Supply Units Roundup. Part VIII

This roundup covers power supply units for midrange and entry-level computers. Such models start from a modest wattage of 300W and a price of $20. We have also included a few powerful PSUs available at affordable prices. All in all we will talk about 17 models from HEC (Ascot), FSP, In Win, Tsunami, Hiper and PC Power & Cooling.

by Oleg Artamonov
12/11/2007 | 10:04 AM

This roundup covers power supply units for midrange and entry-level computers. Such models start from a modest wattage of 300W and a price of $20. Some of the products tested – the Ascot and InWin models, to be exact – come to the market not only individually but also together with same-brand system cases that have earned a reputation for a good quality at an appealing price.


Of course, I couldn’t help including a couple of high-wattage 750W PSUs for enthusiasts and owners of large system cases (you know, it is hard to fit a 500W or higher PSU into a small PC case, see our article called 1000W Power Supply Unit Roundup for details) – you’ll find them at the end of this article.

HEC (Ascot) Silent Pro A-360 (360W) and A-420 (420W)

Ascot is a trademark of HEC/Compucase that is known for turning out products with an appealing price/quality ratio. These PSUs are somewhat more expensive than average, but the high quality and functionality justify the pricing. On the other hand, Ascot PSUs are free from decorations (such as highlighting, transparent windows, etc) and meet the requirements of practical people who just need a good product that works.

Ascot PSUs come together with same-name system cases as well as individually but it is the same PSUs. Moreover, the internal design of the models with different wattage ratings is very similar, so I’ll discuss the A-360 and A-420 both together here.

The PSUs are nothing extraordinary on the outside: a plain gray housing and a punched-out grid of the 120mm fan. The design of the housing is somewhat uncommon, though. A U-shaped cover is usually secured with four screws (five in FSP Group’s products), but there are as many as nine screws here. Perhaps this allows to use a thinner sheet of metal since the additional screws ensure the necessary rigidity and the lack of rattle.

The internal design is ordinary, too. These PSUs lack Power Factor Correction (PFC): active PFC is not provided for even theoretically while the choke of passive PFC is just not installed in the corner. The output voltages are regulated jointly. A UC3843B chip is used as the main PWM-controller; the standby source is based on a TNY267PN chip.

I could find no fault with the quality of assembly and soldering. Everything is neat and tidy here.


The PSUs both comply with the ATX12V 2.0 standard. The combined allowable load on the +12V rail is 25A for the 360W model and 29A for the 420W model. That’s exactly what the standard recommends for PSUs of such wattages.

The PSUs have the following cables and connectors:

The mainboard cable is sleeved; the other cables are tied up with nylon straps.

The problem I can see here is that the PSUs have too few power connectors for SATA devices. I think that a modern PSU can do just fine with only two Molex plugs but must have more SATA connectors. This is a problem indeed since these PSUs are installed into the full-size Ascot 6AR2 and 6AR6 system cases that can accommodate more than a couple of hard disk drives.

You can read the UL certificate number at the bottom of the label: E199442. This denotes Compucase Enterprise Co., Ltd.

The junior model’s cross-load diagrams look good except that the +12V sags 3-4% in the bottom right of the diagram (when the load on the +12V rail is high). The voltages approach the 5% deflection only when there is a great misbalance of overall load towards the +5V rail (the top left of the diagram) which is an unrealistic situation for a modern PC.

The diagrams of the 420W model look much alike to the junior model, but the PSU doesn’t make it to the promised 145W on the +5V and +3.3V rails combined because the +5V voltage sinks below the permissible limit. This is not a serious problem, though. There just cannot be a high load on that rail in a modern PC. So if you want to find a fault with this PSU, you should instead gripe about the +12V voltage sagging 3-4% under load.

The oscillograms of the output voltages look somewhat odd. The +3.3V rail, very calm regularly, is full of short high spikes here. This is usually the consequence of using low-quality capacitors with a high equivalent series resistance that do not cope with high-frequency noise well enough. So, the PSU just barely meets the requirements of the standard in terms of output voltage ripple due to those spikes.

The same thing can be observed about the 420W model. Added to it, there appear spikes on the +5V rail, too. The output voltage ripple on the +12V rail is far within the limit (120 millivolts).

Both PSUs come with 120x120x25mm A1225L12S fans from Hong Sheng Technology with a rated speed of 1800rpm.

The next test in my program is to find the correlation between the fan speed and the PSU temperature. The load is steadily increasing from 50W to the allowable maximum, the PSU working for 20-30 minutes under each intermediary load. Alas, the A-360 passed this test, but the A-420 failed after about 3 minutes of operation under full load:

Quite a large portion of the PSU was burned out, including the PWM-controller and most of its accompanying components up to resistors. The chip itself and a couple of neighboring transistors exploded into pieces.

The 360W model not only worked well under full load but also was rather quiet at that. Its fan speed was lower than 900rpm at minimum load and barely reached 1300rpm at max load.

The senior model is somewhat noisier. The fans being identical, I guess there are different ratings of components in the speed controllers. As I wrote above, the senior model failed at full load and the diagram ends at 350W.

The efficiency is rather low by today’s standards, barely reaching 79%. The power factor is 0.65 on average, which is typical of PSUs without power factor correction.

So, the Ascot A-360 and A-420 are products of moderate quality. The former will make a good PSU for midrange PCs, providing stable voltages at a low level of noise, but you shouldn’t pay extra for the latter. The A-420 doesn’t have better parameters than the A-360 and cannot actually deliver the declared maximum output power. Thus, it has only one advantage – two SATA connectors instead of one in the A-360. By the way, this is the most serious problem of these two PSUs from a user’s point of view. The manufacturers should think about equipping their PSUs with at least three or four SATA power plugs placed on two separate cables. This won’t even make the PSU more expensive to make because the PSU may come with fewer Molex connectors that are quickly becoming unnecessary these days.

HEC (Ascot) Silent Pro A-460 (460W)

I didn’t include this PSU into the previous section because it differs, even though not by much, from the A-360 and A-420.

The A-460 has exactly the same housing as the lower-wattage models of the series: a standard gray color, a punched-out fan grid, and additional fastening screws (you can see their heads on the side panel) that compensate the low rigidity of the thin metallic panels.

The interior is different, even though not fundamentally. The PSU has the same functionality (it lacks PFC and has joint voltage regulation) but uses another PCB.

Well, this difference must be due to the impossibility to install a passive PFC device into the A-460. Most of the A-360’s PCB was intended for it and some components had to be moved forward. In the A-460, there is just no place to fit a PFC device into. Thanks to that, the heatsink with switching transistors (the left one in the snapshot) has become longer, so you can expect this PSU to work successfully under full load, unlike the A-420 model.


This is an ATX12V 2.0 power supply. It provides a max current of 32A (i.e. 384W) on the +12V rail (which is split into two virtual output lines).

The cables are the same as in the Ascot A-420:

The mainboard cable is sleeved; the other cables are tied up with nylon straps.

Again I don’t share the manufacturer’s affection towards Molex plugs. Of course, we have all got used to them in the last decade and there are large stores of such connectors at the storehouse, but why? A new modern PC does not have a single device that would need a Molex. Graphics cards with this connector are long obsolete and PATA drives are about to become such. The assortment of optical drives with a SATA interface isn’t frugal anymore. The PSU manufacturer doesn’t even have to make any effort to transition from Molex to SATA power connectors – they just have to put the other type onto the same cables! Well, I don’t have anything against two or three Molex plugs for the sake of backward compatibility, but you don’t need more of them. I just hope this situation will change as soon as possible.


The PSU’s cross-load diagrams look good but the +5V voltage fluctuates rather too much. Yet even this voltage goes out of the allowable limits in a very small range of loads in the top left of the diagram. Such a misbalance just cannot occur in a modern computer where most of the system is powered by the +12V rail. The +12V rail on its part does well, deflecting by no more than 2% from the nominal value most of the time.

This model has voltage spikes on the +3.3V rail, too. On the other power rails the pulsation is within the allowable limits (which are 50 millivolts for the +5V rail and 120 millivolts for the +12V rail). So, the PSU passes this test, yet with considerable difficulty.

The PSU uses a 120mm fan from Yen Sun Technology (also known as YSTech). This model, KM121225LS, is not listed at the manufacturer’s website, though.

The speed of the fan is changing steadily from 1200 to 2050rpm. Comparing this graph to the one of the A-360 you get another refutation of the popular notion that “the higher the wattage, the quieter the PSU is”. In practice, the manufacturers often achieve the desired higher wattage by installing a higher-performance fan. As a result, a high-wattage PSU proves to be louder than a low-wattage one, especially at low loads, despite having identical speed control circuits.

By the way, the A-460 easily worked under full load: there was but a small difference between the input and output temperatures and I didn’t spot any sign of overheat.

The PSU is only 1% more efficient than the lower-wattage models. This difference fits within the measurement error range as well as within the fluctuation of parameters between different samples of the same PSU, so the A-460 didn’t conquer the 80% peak, either. Its power factor is close to 0.7, which is a good result for a PSU lacking any power factor correction, yet much worse than the power factor of over 0.95 provided by models with active PFC.

Thus, the Ascot A-460 surpassed its low-wattage mates (I mean the A-360 and A-420), delivering more stable voltages and problem-free operation at full load. Its shortcoming is the shortage of SATA connectors (you’ll have to use adapters if you’ve got more than one SATA drive) and a higher level of noise in comparison with the A-360. It means that you shouldn’t try to get a PSU of as high wattage as possible. Instead, you should estimate the needs of your PC realistically and if those needs can be satisfied with a 350W power source (not only office-oriented systems but also rather advanced home PCs with a good CPU and a single graphics card fall within this category), the Ascot A-360 is going to be a better choice.

FSP FSP400-60GLN (400W)

I have been reviewing power supplies from FSP Group quite regularly, but those were mostly boxed products while you can also meet cheaper OEM versions in the shops. They are actually meant to be sold together with a system case or a whole PC, yet you may be interested in them if you don’t care about colorful product packaging.

The FSP400-60GLN belongs to the newest series of ATX12V 2.0 power supplies from FSP. This series is the basis of such boxed models as FSP Optima Pro, FSP BlueStorm II, Zalman ZM460B-APS and others.

The PSU has a plain gray case with a wire fan grid. It lacks any kind of decorations.

FSP released its GLN and HLN series to a surprise to many reviewers: those PSUs could be mistaken for 200W ones judging by the size of the heatsinks, yet they easily coped with two times that load. This is not a secret anymore. FSP could use smaller heatsinks because it also used a large number of parallel-connected diode packs which heated up much less as the consequence. The total weight of the PSU was less than 2 kilos which was important for European users – the value of the EU tax on electronic equipment depends on the weight of the equipment. The other characteristics of the PSUs didn’t deteriorate from that.

Being a junior model in the GLN series, this PSU has a peak output power of 400W. Its heatsinks are perfectly smooth aluminum bars. Small ribbing only appears on the heatsinks of the higher-wattage models of the series. Additional ribbing is also present on the heatsinks of the 460W Zalman ZM460B-APS, which was based on the FSP460-60GLN with quiet operation in mind.

Otherwise, the circuit design of this PSU is ordinary for today: active PFC, a single-ended PWM-controller based on a CM6800G chip with an operating frequency of about 110kHz, and joint voltage regulation.

The specifications are fully compliant with the ATX12V 2.0 standard. The combined load on the +12V rail can be as high as 29A (348W). Thanks to active PFC the power supply supports input voltages from 100 to 240V without a switch. It has no problems with UPSes (I mention this specifically because some older PSUs with active power factor correction, from FSP too, didn’t work right with UPSes).

The PSU offers the following cables and connectors:

The cables are tied with nylon straps.

That’s a depressing sight indeed: a modern 400W PSU with only one SATA power connector (and sometimes you can even encounter its version without any SATA connectors at all!) and with no graphics card power connector. Perhaps FSP invites the customer to choose the more expensive boxed versions of PSUs. For example, the BlueStorm II, based on the FSP400-60GLN, not only has a beautiful blue color of the case but also a broader selection of connectors.

Owners of older PCs should be aware that the FSP400-60GLN has a non-separable 24-pin mainboard plug. You’ll have to use an adapter to plug it into an old mainboard with a 20-pin connector on board.

The new high-wattage power supplies from FSP Group’s Epsilon series didn’t perform quite well in my earlier tests, but the FSP400-60GLN is good in this respect. Its voltages deflect more than 5% only at greatly misbalanced loads. The +12V voltage is good, sagging no more than 2% below the nominal value even at max load.

The PSU is cooled by a Yate Loon D12SH-12 fan that has a rated speed of 2200rpm. This firm’s fans have earned a reputation of inexpensive midrange models. You can get a very quiet or a somewhat noisy sample depending on your luck.

Like in other HLN/GLN series units, this model has a strictly linear fan speed regulation without a minimum threshold (i.e. the PSU doesn’t have a range of loads at which the fan speed remains constant). Although the fan starts out from a low 930rpm, it then accelerates quite greatly, making the PSU average in terms of noisiness. Many users are going to be perfectly satisfied with it in this respect, though.

The PSU efficiency is good, being over 80% throughout most of the load range. The power factor is 0.95 on average.

So, the OEM version of the FSP400-60GLN is a good-quality power supply with stable parameters. However, its limited selection of connectors doesn’t make it suitable for PCs with top-end graphics cards or HDD arrays – you’d have to use a lot of adapters or your soldering iron to power such a configuration up. If neither is acceptable to you, you should look at the boxed versions of FSP power supplies (e.g. at the BlueStorm II which is based on the FSP400-60GLN) or at other manufacturers’ products.

I guess there is a user category that may be interested in this particular model, though. The FSP400-60GLN is one of the cheapest PSUs with active PFC selling in retail. If you live in a rural area with an unstable electricity supply, the PSU will come in handy because, unlike other models, it can easily work in such a power grid without UPSes or voltage stabilizers.

InWin IP-P300AQ2-0 (300W), IP-P350AQ2-0 (350W), IP-P400AQ2 (400W)

I have reviewed power supplies from InWin on our website before as they are quite popular among the users. InWin offers not only PSUs but also inexpensive, yet good quality, system cases. However, in my last article devoted to In Win PSUs I regretted the fact that the firm shipped its modern ATX12V 2.0 models only as boxed products while the system cases still came with outdated ATX12V 1.3 power supplies.

And at last InWin’s product line-up has been complemented with low-wattage (staring from 300W) PSUs complying with the ATX12V 2.0 standard and selling both in system cases and separately.

The first three models with similar names and an identical platform will be reviewed all together.

The PSUs have an ordinary gray case with a wire grid of a 120mm fan. The mains voltage switch indicates that these models lack active PFC. By the way, they may come without such a switch. Its place is sealed then and the PSU only supports an input voltage of 200-240V.

The circuit design is quite normal for today, with an UC3843B PWM-controller and a TNY276PN-based standby source. The PSU doesn’t have PFC (there is no place left even for a passive PFC device) or dedicated voltage regulation.

You can see that the PCB of the 400W model is no different. The PSUs belong to the same series and share the same circuit design except that the capacitors in the higher-wattage unit are a larger size and capacitance.

I can find no fault with the assembly quality. Everything is simple but neat here.

The junior model indeed complies with the ATX12V 2.0 standard although the allowable load on the +12V rail is somewhat lower than described in the standard (20A against 22A). That’s a negligible difference, though.

The same goes for the 350W and 400W models. These PSUs comply with the ATX12V 2.0 standard as well, but the allowable load on the +12V rail is somewhat lower than recommended. Take note that the allowable load on the +12V rail grows up along with the overall wattage of the PSU whereas in the previous, ATX12V 1.3, generation of InWin PSUs, e.g. in the AJ series, that load was 18A irrespective of the overall wattage.

Each of the three PSUs has the same set of cables and connectors:

The cables are tied up with nylon straps.

It’s good that even the 300W model has a graphics card connector and two SATA connectors, yet still I’d want to see at least four SATA plugs and on two separate cables. The cables are not long, but that’s rather an advantage for small and medium system cases.

The cross-load diagram looks good overall but the +12V voltage sags 3-4% below the nominal value under load. That’s quite a lot. A top-end graphics card may prove sensitive to such sagging even though it remains within the allowable 5% limit. On the other hand, I don’t think anyone will use a junior model of an inexpensive PSU to power up a top-performance graphics card. The +5V voltage bottoms out under high loads as well, yet that’s not critical since there just can’t be a high load on the +5V rail in a modern PC.

The diagrams for the 350W and 400W models are almost the same. It is only at greatly misbalanced loads that the voltages violate the allowable limits, but the +12V and +5V voltages sag when the respective power rail is under high load.

The output voltage ripple is similar between the PSUs, so the diagram above is for the senior model at its full load of 400W. The ripple is within the norm, twice lower than the permissible limit on every power rail.

The PSUs are equipped with identical fans (ARX FD1212-S3112E) and have identical noise characteristics as the consequence. By the way, that’s another refutation of the myth that a higher-wattage PSU is always quieter than a lower-wattage one.

The fan is working at a constant speed at loads below 200W and then accelerates in a linear manner. The PSUs are average in terms of noisiness. The initial speed of the fan is rather low (yet it is lower by some 200rpm in the really quiet PSUs) but, unfortunately, ARX fans are rarely good quality. You often get a sample with noisy bearings or an imprecisely balanced impeller.

The PSUs have an efficiency of slightly over 80% at the maximum, but the average efficiency is good, especially for inexpensive entry-level PSUs. The power factor is a little over 0.65 as you can expect from PSUs without power factor correction.

So, InWin has begun a mass production of power supplies that comply with today’s requirements such as the ATX 12V 2.0 standard, a modern circuit design including a specialized PWM controller in the standby source, an acceptable selection of cables and connectors. Still, these PSUs are rather meant for mainstream and entry-level PC systems. They are not exceptional in terms of electrical parameters or noise level, but can do quite well in an office PC or in a home PC of an undemanding user especially as they sell not only individually but also in InWin system cases, which have an appealing price/quality ratio.

InWin IP-P350GJ2-0 (350W)

Despite its looking exactly like the above-discussed AQ series, I’m reviewing this PSU separately. Its different letter index must mean something.

The IP-P350GJ2-0 comes in three versions: a PSU alone, a boxed version (differs from the previous version in having a power cord, a user manual, and four screws included with it), and in an InWin system case.

As for minor differences, the PSU doesn’t have an input voltage switch as it only supports an input voltage range of 200-240V. It also has a protruding fan grid – not quite comprehensibly because it is recessed in the other series of InWin PSUs. The protruding grid may prevent you from installing the PSU into some system cases. It is simple to reinstall the grid, but the PSU is sealed with a sticker. If the PSU fails and the sticker is damaged, you may have problems with the warranty department.

There’re a few differences from the AQ series on the inside, too, but they only concern some of the components employed and the placement of the elements on the PCB. The circuit design is overall the same. This is a PSU without power factor correction (although it allows for an installation of a passive PFC device) and with joint voltage regulation. The PSU uses a UC3843B PWM-controller and an ICE2A0565Z-based standby source.

The PSU seems to have lower mounting density than the AQ series, but that’s only an illusion created by the smaller heatsinks of the GJ model. These are simple aluminum bars with “fingers” at the top. Well, it is no good to come to any conclusion about the cooling efficiency judging by the appearances only.

The total output power being 350W, the allowable load on the +12V rail is 300W (25A). This is higher than in the IP-P350AQ2-0 and fully compliant with the ATX12V 2.0 standard. The power rail is divided into two virtual output lines.

The PSU is equipped with the following cables and connectors:

The cables are tied up with nylon straps.

As you may have guessed, I’m going to complain about the shortness of the cables (I can remember that in InWin’s own system case – the rather large X710 model – the native PSU’s cables were not even long enough to reach for the HDDs located in the HDD cage!) and the lack of SATA connectors that are also placed on a single cable (in other words, you’ll have to use adapters if you’ve got one HDD and one optical drive because there is usually more than 15cm of distance between their power connectors in a normal system case).

But let’s proceed to the tests now.

The output voltage ripple is low even at full load. It is safely within the allowable limits.

The cross-load characteristics look very good – better than those of the above-discussed AQ series. The +12V voltage only sags more than 2% at greatly misbalanced loads, which are not possible in a real PC.

The PSU is cooled with a fan from InWin’s traditional supplier ARX, the FD1212-S3142E model. Alas, I have to note again that ARX fans are not always quiet even at low speeds.

The fan speed remains constant most of the time except for near-maximum loads but the PSU is not really quiet. The speed is not really low while the rather noisy bearing of the ARX fan is buzzing quietly, yet audibly.

The efficiency of this PSU breaks no records, but stays at a good level of 80% on average. The power factor is low, not making it even to 0.65.

The InWin IP-P350GJ2-0 is a good-quality, neat and inexpensive mainstream PSU for office PCs and undemanding home users. It complies with the ATX12V 2.0 standard, delivering the necessary parameters and declared output power. On the downside are the short length of the cables, the shortage of SATA plugs and the lack of a graphics card connector, and the use of inconsistent-quality fans.

InWin IP-P450DJ2-0 (450W)

This model from InWin differs from the previous one not only with its wattage but also with a letter in the model name.

There’s little difference externally. The PSU is assembled in the same housing as the IP-P350GJ2-0 except that the fan grid is now flush with the top panel and cannot become a problem when you are installing the PSU into your system case.

The internal design resembles the AQ series models discussed above. The DJ series is almost an exact copy of them.

The main difference between the AQ and DJ series is the size of the heatsinks which are smaller in the DJ unit and made from bars with molded “fingers” at the top. This doesn’t tell anything about the quality of cooling, though. Larger heatsinks sometimes provide worse cooling as they create an additional aerodynamic resistance to the air flow.

Perhaps you’ve already spotted the trick. The +12V rail is known to be the most important one for a modern PC. The 350W IP-P350GJ2-0 model had a load capacity of 300W on this rail. And the 450W IP-P450DJ2-0 turns out to have exactly the same load capacity of that rail. As a result, the effective load capacity of these two PSUs (in other words, the amount of power a modern PC can get from them considering the typical load distribution among the different power rails) is identical.

The PSU is equipped with the following cables and connectors:

Alas, we’ve got the same thing here. The PSU has a lot of Molex connectors for PATA drives but does a modern PC need that many? The user is just going to use adapters on most of those Molexes.

The output voltage oscillogram for the low-voltage rails shows short spikes at the moments of switching the inverter. Those spikes are higher than the allowable limits. I guess this is the consequence of using rather poor electrolytic capacitors, which are also not shunted by ceramic capacitors, in the PSU’s output rectifier.

The cross-load diagram looks like those of the AQ series models and worse than the diagram of the GJ model whose +12V voltage didn’t sag that much under load.

The PSU is cooled with an ARX FD1212-S3142E fan.

Its speed is almost constant at low loads but then begins to grow up linearly. Coupled with the not-very-high quality of ARX fans, it makes this PSU average in terms of noisiness.

The PSU is 80% efficient and its power factor is 0.65 on average as is typical of PSU without any power factor correction.

I could write the same about the IP-P450DJ2-0 as about the other InWin PSUs discussed in this review if it were not for one thing. From a practical point of view, it is no better than the cheaper IP-P350GJ2-0. They both have an identical load capacity of the +12V rail while the other rails are much less important for a real-life modern PC. Thus, purchasing the more expensive and allegedly higher-wattage model doesn’t look wise to me.

Tsunami Hercules A300M-C (300W)

The Taiwan-headquartered Tsunami is offering a broad range of PC components, including power supplies.

The Hercules A300M-C is a junior model in Tsunami’s product line-up. One glance at the exterior of the case helps identify the actual manufacturer, FSP Group.

The interior confirms this supposition. This is a product from FSP Group’s very first and very successful series of ATX12V 2.0 power supplies called FSPxxx-60THN/THA (the two versions differ in the type of the fan, 120mm or 80mm). When the more modern GLN series was introduced, the FSPxxx-60THN/THA models were relegated into the low-end sector and renamed as ATX-xxxPN. Lately those PSUs have been used as the basis for various low-end products under different names (for example, FSP300-60PNR) supplied to PC integrators and OEMs. The Tsunami A300M-C must be one of such cheap versions.

Some time ago I already tested a similar model from FSP, the ATX350F-C.

The mentioned cheapening concerns the housing (thinner steel and a punched-out fan grid) as well as the electronics (lower ratings of the capacitors, smaller heatsinks, a simplified fan speed management). Although such simplified PSUs deliver the same output power as their more expensive counterparts, they are mostly meant for entry-level PCs whose power requirements are far below the PSU’s maximum output power.

The PSU complies with the ATX12V 2.0 standard. A combined current of 22A is allowed on the +12V rail just as recommended by this standard for 300W power supplies.

The PSU is equipped with the following cables and connectors:

The cables are tied up with nylon straps.

The drawbacks I can note here are that the PSU has only two SATA connectors on one cable and that the cables are too short. In fact, this PSU will only be good for a microATX system while an owner of a full-size case may have problems with it. The graphics card connector looks somewhat odd here as I don’t think anyone will buy a junior PSU model for a system with a top-performance graphics card.

The high-frequency ripple of the output voltages proved to be low even at full load.

It is accompanied with low-frequency ripple at the double mains frequency, i.e. at 100Hz in this case, but the total ripple doesn’t violate the permissible limits and the PSU complies with the requirements in this respect.

The cross-load diagram doesn’t look so good. The +12V voltage depends on the load and sags heavily when the load is high. On the other hand, all the three voltages are going to be close to their nominal values in a PC with a total consumption, for example, of 200W in which 160W falls on the +12V rail.

The PSU is cooled by an 80x80x25mm fan (Adda AD0812MS-A70GL). Adda fans have earned a good reputation. Products from that firm are used even in the quietest of PSUs.

The speed adjustment range is as small as 10% which indicates a greatly simplified fan controller. Anyway, the fan is high quality and not very fast, making the PSU rather quiet at work – you can only hear the hiss of the air flow.

The A300M-C heats up a lot. The difference in the air temperature exceeds 10°C and I could feel the characteristic smell of hot insulation when the PSU was working at full load. It passed the test without failure, though.

The PSU is only 77% efficient. The circuit design which dates back to FSP Group’s very first ATX12V 2.0 series is becoming outdated. The power factor doesn’t make it to 0.6 in a broad range of loads. Such PSUs won’t be a good choice for an office with many machines as they “pollute” the supply mains greatly.

In fact, the Tsunami Hercules A300M-C is an entry-level PSU for low-end PCs with a power consumption of 150W and less (considering the reduced consumption of modern dual-core CPUs, this number can accommodate a rather advanced graphics card even). It will satisfy you with its stable and rather quiet operation under such conditions.

On the downside, the PSU has very short cables, being obviously meant for microATX system cases, and a very low power factor. The power factor is unimportant for a home user, but can create a considerable extra load on the electric mains in an office with a lot of PCs.

Important Note

Tsunami is selling the Hercules PSN-300P alongside the Hercules A300M-C.

Although it comes in the same box as the A300M-C (some marks on the side panel are different), this PSU has nothing to do with FSP Group and even with the ATX12V 2.0 standard. Take note that its maximum allowable load on the +12V rail is only 168W, i.e. almost 100W lower than that of the A300M-C.

I didn’t test the Hercules PSN-300P model and cannot tell you about its real characteristics and quality. But if you want to purchase a PSU manufactured by FSP Group, you should make sure the label contains the right model name.

Tsunami Hercules AX400-PN (350W)

Although the number in the model name is bigger by 100 than the number in the previous model’s name, the difference in wattage is only 50 watts. The AX400-PN is a 350W power supply. The number 400 is written on its label, too, but it is the peak output power. In other words, you must not put a load of 400W on this PSU for longer than 1 minute.

The exterior is quite explicit about the actual manufacturer of the PSU. It belongs to FSP Group’s ATX12V 2.0 series and is cooled with one 120mm fan.

The interior design proves my point. The Hercules AX400-PN is based on the FSP ATX-350PN (note that FSP declares the continuous output power while Tsunami, the peak one). It is an ATX12V 2.0 power supply without PFC (a passive PFC device is installed into the ATX-350PNF model, and active PFC is not provided in this series at all) and with joint regulation of voltages.

This PSU is not a simplified version of something. It’s got a wire fan grid, slightly larger heatsinks and a twice higher capacitance of the high-voltage capacitors in comparison with the above-discussed A300M-C.

The PSU can yield a maximum continuous output power of 350W, and 300W (25A) of it can be delivered through the +12V rail divided into two virtual output lines.

The PSU is equipped with the following cables and connectors:

The cables are tied up with nylon straps.

Again, the short length of the cables is the main drawback of the PSU. It may be insufficient for a full-size system case.

The output voltage ripple is within the allowable limits at a load of 350W. There’s no additional low-frequency pulsation at the output: this must be due to the increased capacitance of the high-voltage capacitors in comparison with the A300M-C model.

The “green zone” for the +12V voltage has moved rightward in the cross-load diagram and this voltage doesn’t sag even at high loads. That’s another advantage over the A300M-C model. The +5V voltage is somewhat higher than necessary in the load range typical of a modern PC, but it never violates the allowable limits.

The PSU uses a 120x120x25mm fan (Yate Loon D12SH-12).

The fan is rotating at a constant speed until a load of 250W. Then its speed begins to grow up. If the initial speed were some 300rpm lower, the AX400-PN might be regarded as a quiet PSU but it is only average in this respect in reality.

The efficiency reached 80% at one point but kept a little below that value on average. The power factor is higher than with the A300M-C, but didn’t make it to 0.65.

Thus, the Tsunami Hercules AX400-PN is an improved version of the Hercules A300M-C: an output power higher by 50W, no signs of overheat when working at full load, and improved electric characteristics (particularly a more stable +12V voltage). This PSU will be a good choice for a microATX system including a rather advanced CPU and graphics card. Unfortunately, the short length of the cables may be an obstacle to using the AX400-PN in full-size system cases.

Important Note

Like with the A300M-C, Tsunami produces several Hercules PSUs with a peak output power of 400W. Besides the AX400-PN, I know of the L&C LC-B400ATX:

This model complies with the outdated ATX12V 1.2 standard, so you should check out the marking if you want to buy the ATX12V 2.0 unit manufactured by FSP Group. Both PSUs come in identical Tsunami Hercules boxes.

Tsunami Extreme AX400-PN (350W) and AX450-PN (400W)

The model names indicate a relation to the above-discussed Tsunami Hercules AX400-PN.

Indeed, they only differ externally with the color of the paint. The Hercules is gray while the Extreme is black.

The internal design is identical. That’s the well-known FSP ATX-xxxPN series. Tsunami declares the peak output power in the model name while FSP, the continuous one. Thus, the Extreme AX450-PN is based on the FSP ATX-400PN while the Extreme AX400-PN is based on the FSP ATX-350PN.

These two PSUs being identical in most of their parameters and internal design, I will be discussing them both together here.

They comply with the ATX12V 2.0 standard, their labels specifying not only the peak but also the top continuous output power. The PSU can yield just half a hundred watts less on the +12V rail (split into two “virtual” output lines) than its total output power.

The PSUs have the following cables and connectors:

It’s easy to guess my criticism here. There are too few SATA connectors (only one in the junior model and two on the same cable in the senior one). The cables are also rather short.

The cross-load diagram of the junior model doesn’t look neat due to the stable, but consistently too high, +3.3V voltage. The +5V voltage is also too high when the load is misbalanced towards the +12V rail as is typical of the modern PC.

The senior model looks somewhat better but the +12V voltage bottoms out slightly under load.

The output voltage ripple is within the norm, although very close to the limit on the +3.3V rail.

Each PSU uses a 120x120x25mm fan (Yate Loon D12SH-12).

The fan has a constant speed at low loads but accelerates after a certain threshold. Like the Hercules AX400-PN, the Extreme series models are average in terms of noisiness. The fan is quite audible at 1200rpm.

Alas, the AX450-PN would shut down after working for 3-4 minutes at a load of 375W although its continuous load is declared to be 400W. Perhaps Tsunami uses a 350W rather than a 400W unit from FSP for its AX450-PN because I didn’t see PSUs sold under FSP Group’s own brand behave like that.

The efficiency is slightly above 80% while the power factor barely notched 0.65.

So, the Extreme series only differs from the Hercules with the color of the housing and the availability of a 400W model. Unfortunately, the company didn’t make the cables longer or increase the amount of connectors. The rest of the characteristics are identical because both series are based on the same PSUs manufactured by FSP Group.

Hiper Type M HPU-4M670-SU (670W) and HPU-4M730-SK (730W)

Power supplies from Hiper stand out among the PSUs included into this review with their wattage as well as price, but I didn’t want to wait with the publication of their test results until there is a proper company. The 4M670 and 4M730 models are based on the same platform and will be discussed both together.

The PSUs have one 80mm fan – this form-factor isn’t very popular nowadays. The exterior is imposing overall: a robust heavy case made from thick steel and painted a black matte color. If the developer wanted to make this model look serious and solid, he succeeded indeed. Although weight is not an indicator of quality when it comes to PSUs (for example, a cheap no-name PSU with a heavy choke of passive PFC can weigh more than a high-quality expensive unit with active PFC), yet the heaviness of the Hiper Type M is kind of reassuring.

There are two PCBs inside, with the components facing each other. The circuit design is up to today’s requirements including active PFC and dedicated voltage regulation.

Most of the PSU’s high-voltage section is located on the top PCB, namely the input rectifier, active PFC, PWM-controller, and standby source. The bottom PCB carries the main switching transistors, power transformer, and the low-voltage section with rectifiers, chokes and capacitors.

Most of the junctions use connectors, yet you cannot detach the top PCB without a soldering iron: the wire from the 220V mains connector is dead soldered into it for some reason.

Speaking generally, this dual-PCB design has both pros and cons. On one hand, the larger the total area of the PCBs, the easier it is to wire them using less expensive, larger, components. On the other hand, such PSUs often have a higher component density than their single-PCB counterparts which is not good for cooling and calls for a high-performance fan. Moreover, a 120mm fan cannot be installed in such a PSU at all. As a result, two PCBs is not a widespread solution although I have seen it in FSP Group’s PSUs (FSP460-60PFN and OCZ ProXStream OCZ1000PXS).

On closer inspection of the interior of the Hiper Type M I was shocked at the quality of manufacturing. The PSU is overall neat, but there are some things I just don’t know what to think of, considering that our labs received off-the-shelf products from a shop, not some engineering samples.

Photo One: the HPU-4M730-SK unit. Two surface-mounted resistors are obviously soldered in manually and awry (the top one is skewed by some 30 degrees while the bottom one doesn’t lie on the PCB but hangs on the solder). There are traces of flux and burnt spots all around.

Photo Two: the HPU-4M730-SK unit. Two resistors are soldered one above the other. First, this solution must not be used in a serially produced product at all. Second, the soldering is very untidy: skewed, with traces of rosin and burnt spots.

It’s hard to explain such things. Perhaps the manufacturer didn’t have the equipment necessary to solder surface-mounted elements automatically and the workers that replaced such equipment were not qualified enough. Perhaps it was necessary to quickly change something in the PSU that had already been produced in mass quantities. Perhaps they had to assemble the PSU out of the components available at the storehouse but not of what was really appropriate. Anyway, I think that this manufacturing quality is not permissible for a retail product (and for a not-very-cheap product, by the way). I won’t tell you anything about the reliability of such PSUs – the photos above are quite self-explanatory. One thing is certain, though. The manufacturer has no quality assurance at all or it is limited to a formal check like “if it has started up, then it’s fault-free”.

Moreover, I can’t be 100% sure without a chemical analysis but the characteristic shimmer of the manual soldering in the second photo may indicate the use of ordinary lead solder while the PSU overall uses modern lead-less, RoHS-compliant, solder (the solder of the neighboring elements is matte, indicating the lack of lead). If this supposition is true, I’d like to remind the manufacturer that mixing two types of solder provokes the risk of rapid corrosion in the spot of contact between them.

By the way, that’s not the first time I express my complaints about the soldering quality in Hiper PSUs. In one of the previous articles I pointed out the untidy soldering of the active PFC device in the Hiper Type R HPU-4M480.

And now let’s read the specs of the PSUs.

The label of the junior model doesn’t make it clear how the wattage of 670W is arrived at. The total of the specified numbers (635W + 9.6W +15W) is about 660W. 10W is not a great difference, but anyway.

The PSU can yield up to 465W or a little less than 39A over its +12V power rail divided into four “virtual” output lines.

Note that the overall output power is higher by only 60W in this model, but the load capacity of the +12V rail is higher by over 200W. The combined current on the four “virtual” output lines is as high as 56A now. Since a modern PC puts a stress on the +12V rail, this is a hefty addition that greatly increases the real load capacity of the PSU.

The total of the specified peak loads proves to be lower than the overall wattage of the PSU again – this time it is lower by 20W.

The PSUs are equipped with the following cables and connectors:

Included with the PSUs are:

The cables are all sleeved.

Alas, Molex connectors for PATA drives are domineering in these PSUs, too. Although I’m now discussing products of a much higher price category than above, they do not have native SATA power connectors at all, only a set of adapters in the box. It seems absurd to me because a truly modern PC doesn’t have a single device powered by a Molex connector! I prefer Tagan’s approach with a lot of SATA plugs on the cables and a few small adapters for Molex connectors in the kit.

The Type M 4M670 and 4M730 proved to be among the few PSUs that still have problems with UPSes. Working together with an APC SmartUPS SC 620, these PSUs behaved normally at loads up to 350W and 260W when powered by the mains and the batteries, respectively. The UPS would keep the PSU running for 10-20 seconds at a load of 260-320W but then would report overload. At a load of over 320W the UPS would shut down instantly when switching to the batteries.

The output voltages are almost ideally stable. The +12V voltage never deflects by more than 1%! The +5V and +3.3V voltages are somewhat worse, but never exceed the allowable deflection of 5% in any point of the diagram even at greatly misbalanced loads.

The senior model is as good. Its area of allowable loads has stretched out along the X-axis and transformed from a rectangle into a trapezium – this is due to the above-mentioned 200W addition to the load capacity of the +12V rail.

The output voltage ripple is low even at full load, never approaching the limits.

Each of the PSUs is cooled with an 80x80x25mm fan (Adda AD0812HB-A76GL).

In the junior model the fan starts out at a speed of below 2200rpm and keeps it until a load of 300W. I won’t call this PSU noiseless, yet it only becomes really loud at a near-maximum load when the fan speed is approaching 3000rpm.

The senior model is somewhat noisier, probably due to the deviations in the component ratings. The difference in the fan speeds is only about 100rpm. This fan accelerates later, at a load of over 400W.

The senior model is over 80% efficient throughout most of the load range, reaching 83% at the maximum. That’s a good result for today. The junior model is about 1% less efficient. The power factor is easily above 0.95 thanks to active PFC.

So, the Hiper Type M power supplies left an ambiguous impression on me. They boast good parameters, superb stability of the voltages, quiet operation but all of this seems to be negated by the soldering defects I found in them. Moreover, the Type M models have problems with UPSes and lack more SATA plugs among the native connectors. It’s rather odd to see a high-wattage and expensive PSU that makes the owner of a simple modern system (with one HDD and one optical drive) use two adapters.

Hiper Type R HPU-4S730-MU V2 (730W)

While the two previous models from Hiper represented the classic design, the Type R HPU-4S730-MU V2 is something exceptional and even unique. Look for yourself:

Most of the PSU cables (all of them except for the mainboard cable, to be exact) are detachable, but plug into the top panel of the PSU rather than into its rear panel (I mean the top panel in the snapshot above – it is going to become a bottom panel when the PSU is installed into a system case).

The cables have handy round connectors that automatically lock in place when you plug them in. To detach a cable, pull at the ring on the connector. The cable won’t go out otherwise, so it cannot fall out of the connector even if you pull at the cable accidentally.

I can see two problems with this implementation of detachable cables. First, few manufacturers are aware of the rule demanding that all live connectors must be female connectors to avoid the possibility of the contacts being closed with a stray thing. Hiper doesn’t know that rule, either. If a metallic thing such as a screwdriver, wire or something falls into the connector of the operating PSU, there will be a short circuit.

Take a look at a typical modern system case. There are just a few centimeters of space between the PSU and the huge CPU cooler (and systems the discussed PSU is meant for are unlikely to have a small CPU cooler). The detachable cables of the Type R just won’t fit in there in the worst case. In the best case, the cables will hang above the CPU cooler, worsening its operation, increasing the noise, and putting the whole system at risk since you don’t want any extra things around your fans. Thus, the original idea proves to be not only useless but simply impractical except for very large system cases in which there is a lot of free space between the top of the CPU cooler and the bottom of the PSU.

The PSU is shipped in a plastic box such as used for storing and carrying various tools. You may want to use the box for that purpose as well after you’ve taken the PSU out of it.

The detachable cables are packed into a small fabric pouch with a zipper. Of course, they would be just as safe in a standard polyethylene pack, but this original approach to packaging is sure to provoke positive emotions on the user side.

Except for the removable card with the output connectors, the internal design is very much alike to that of the UltraProducts ULT-XF800S. The only difference is the shape of the heatsinks due to the need to leave a place for the card with connectors.

The PSU follows a dual-transformer design but its implementation is simple and unsophisticated: two transformers, two switching transistors, but a single shared PWM controller. As a result, although each transformer services its own set of output lines, it is not independent of the other. If the load on one transformer changes, the PWM-controller adjusts the operating frequency accordingly. And since there is only one controller, the frequency is changed on the other transformer as well. In other words, the HPU-4S730-MU is not much different from the ordinary topology with a single transformer and joint voltage regulation.

I didn’t find such gross problems with soldering quality here as with the HPU-4M730-SK, yet I have a few complaints about this PSU as well. Some components, particularly the connectors and large elements, are not installed neatly. There is too much of solder there that forms large drops on the contacts.

This time the totaling of the numbers printed on the label doesn’t provoke any controversies. The PSU has a continuous output power of 730W and a peak output power of 780W. It can provide a current of 56A across its +12V rail, which is divided into four “virtual” outputs.

The PSU has the following cables and connectors:

Included with the PSU are:

Yet another PSU comes without “native” cables with SATA connectors – you have to use adapters.

Like the above-discussed Type M series PSUs, the Type R 730 features active PFC but it has no problems with UPSes. Working with an APC SmartUPS SC 620 the PSU behaved normally at loads up to 350W and 315W when powered by the mains and by the batteries, respectively. The UPS switched to the batteries without problems.

Alas, the output voltage ripple is not a strong point of this PSU. The oscillogram above was recorded with a time-base of 2ms/div at full load. You can see that the voltage ripple was as high as 150 millivolts on the +5V rail (the allowable maximum being 50 millivolts), over 350 millivolts on the +12V rail (the allowable maximum being 120 millivolts), and up to 100 millivolts on the +3.3V rail (the allowable maximum is 50 millivolts). That’s a catastrophic failure that actually means that the PSU cannot work at that load.

When the load is reduced to 520W, there are still voltage spikes in the diagram, but they are within the acceptable limits.

I also recorded an oscillogram with a time base of 10 microseconds/division under the same load of 520W at the moment of maximum pulsation: you can see it is within the allowable limits. But again, this result could only be achieved at a load which was over 200W lower than the maximum permissible load of the tested PSU.

There are problems with the cross-load characteristics, too. The +12V voltage is initially set at 12.5V and lowers to the required level only as the load grows on the corresponding power rail. It doesn’t violate the allowable limits, though, and it’s all right with the +5V and +3.3V voltages.


The PSU uses two fans made by Young Lin Tech: an 80x80x15mm DFB801512H and an 80x80x10mm DFC801012H. It’s not quite clear why the case is perforated with this type of cooling (one fan is sucking the air in and the other is exhausting it). I think it only worsens the cooling of the heatsinks since the air doesn’t flow along them but passes freely through the top panel.

The speeds of the fans are adjusted in sync and differ as much as the fan models differ between each other. Although the speeds are not high, the PSU doesn’t seem quiet with its two fans and a high aerodynamic resistance of the internal components that make the air flow audible. So, the PSU is just average in terms of noisiness.

The efficiency is good, being generally higher than 80%, but the power factor plummets to very low values at low loads despite the active PFC. The reason for that is the improper functioning of the active PFC device. It draws the current from the mains in nearly rectangular impulses, which is better than the short spikes of PFC-less PSUs but still far from a sinusoid.

Thus, the Hiper Type R HPU-4S730-MU V2 is a product from the “they tried their best but didn’t succeed” category. Its original, even unique, design proves very improper for a majority of system cases. The manufacturing quality provokes some criticism. And the main problem is that it cannot cope with a load over 520W, which is 210W below the specified maximum. If the load is higher than that, the output voltage ripple rises up to a catastrophic level, being two or three times as high as the allowable maximum. 

PC Power & Cooling Silencer 750 (750W)

The final product to be reviewed in this article is the 750W Silencer from the respectable PC Power & Cooling, which has been recently bought by the no less respectable OCZ.

You can’t pass by this power supply uninterested. It is painted a bright red color, which is most unusual for PC power supplies. Unfortunately, the quality of the paint isn’t high. It is scratchable and peels off in small pieces.

It is easy to identify the real maker of this PSU. It is Seasonic that should be familiar to our readers by the Seasonic S12 and Antec NeoHE models. By the way, the Silencer 750 is closer to the latter model in its design, being cooled with a single 80mm fan.

The circuit design is up to today’s requirements: ATX12V 2.0, active PFC, dedicated voltage regulation. The PSU is neatly assembled – I have no gripes about that.

The manufacturer doesn’t use the “virtual” splitting of the +12V rail into multiple output lines. The label declares all 60A (720W) this rail can yield. I want to remind you that the implementation of multiple output lines is only done to comply with a safety regulation and has no effect on the stability or other electrical characteristics of the PSU.

This PSU has the following cables and connectors:

At last there is a PSU with a reasonable amount of SATA plugs! Well, I would even remove one cable with Molex connectors altogether or replace it with SATA.

As is expected from a PSU certified for the use in a CrossFire system, this one has four graphics card connectors, two of which can be plugged into both 6-pin and 8-pin connectors on the graphics card.

The output voltage ripple is far below the allowable maximum even at full load of 750W.

The cross-load diagram looks very good. The +5V voltage is worse than the others, but never leaves the allowable range at any loads, even greatly misbalanced ones.


There is a Silencer sticker on the case of the employed fan, but its rotor carries the original manufacturer’s sticker. So, it is an Adda AD0812UB-A71GL. Fans with the UB index are the fastest ones in this firm’s product line-up, and the noise characteristics of the PSU will depend on its fan speed regulation.

Fortunately, it’s all right here. The speed is not higher than 1500rpm at loads up to 500W – that’s not high for an 80mm fan. Then it grows up quickly together with the load, protecting the PSU from overheat. So, the Silencer 750 is very quiet at average loads. As for high loads, a system that can create such a load will not be quiet irrespective of the PSU.

The PSU is over 85% efficient, which is an excellent result. The efficiency is far above 80% across most of the load range. The power factor is over 0.95 as you can expect from a PSU with a properly implemented active PFC.

So, the Silencer 750 from PC Power & Cooling is an excellent PSU for people who really need a high-wattage power source. Besides superb electrical characteristics, a somewhat unusual appearance and a full selection of cables, it features a very quiet operation at low and medium loads, which is not a common attribute of high-wattage PSUs.

My single suggestion for the manufacturer is to use a more durable paint but retain its remarkable color :).


This roundup has covered quite a lot of PSUs of different wattage, but mostly low- and mid-wattage models intended for typical office and home PCs.

PSUs from HEC (Ascot) and InWin are not anything exceptional but can make a reasonable choice for the mentioned category of PC systems especially as they come together with system cases that have an appealing price/quality ratio. The Ascot A-420 and InWin IP-P450DJ2-0 are not as good as the others, though. The former doesn’t deliver the promised output power while the latter has the same effective load capacity as the cheaper IP-P350GJ2-0. I want to single out the Ascot A-360 as a very quiet PSU if you are satisfied with the wattage provided by it.

The FSP FSP400-60GLN has good characteristics but a very limited selection of cables and connectors. It is going to be interesting for people who need a PSU with active PFC and a full range of input voltages for as little money as possible.

Tsunami debuted in our reviews with a whole series of PSUs based on models developed by FSP Group but from an older series that differs greatly from the mentioned new GLN series. That’s actually all I can tell you about them because we’ve published a lot of reviews of such PSUs from FSP and their derivatives. These are good, stable, reliable products but only suitable for microATX cases in Tsunami’s version because of the short cables. You have to be careful when shopping: the company is selling PSUs of different models and from different manufacturers in same-looking boxes.

Hiper disappointed me really. I have complaints about the assembly quality of each one of the three tested units, and even very serious complaints about one of them. Moreover, the Type R HPU-4S730-MU V2 just couldn’t work normally at a load of over 520W while the sets of connectors call for a modernization in favor of SATA plugs instead of PATA ones.

And finally, PC Power & Cooling deserves to be on the podium with its quiet, powerful, stable and pretty-looking Silencer 750. It is different from the other PSUs in this review and it wouldn’t be correct to compare it with the PSUs from Ascot and InWin that are only half of its wattage. Anyway, if you are looking for a really high-wattage PSU, you should definitely consider this one.