Introduction

The power supply market has certainly changed a bit over the last 18 months.  Several months ago, we took a quick cross section of where the power supply market was going, with samples from Antec, Enermax, ThermalTake and Vantec.  Because this represented such a small cross section of the market, almost immediately we began working on a larger, more thorough examination. 

Directron.com let us pick one of every new power supply off their shelves in order to put together a sample of 18 of the newer power supplies on the market right now.  We took a wide range of low end to high end power supplies from just about anyone we found a phone number for. We then ran several exhaustive tests on these power supplies, including a benchmark that checks average memory errors due to power supplies. Without further delay, we present our 18 power supplies.

A lot of Sparkle’s power supplies share similar components to Fortron, but that does not mean they have not developed their ability to innovate independently.  We were pretty amazed when Sparkle told us they managed to cram a 120mm fan inside a standard ATX power supply. Getting a 120mm fan is not uncommon, but enclosing it within an ATX housing is.

We are particularly interested how this PSU will fare in the noise test. A 120mm fan can push more CFM (cubic feet per minute) of air than an 80mm fan, while doing so at a slower speed.  Check out our sound test to see how this might benefit you.  An interesting note about this power supply is that the fan starts up at full revolutions, then throttles down to the correct RPM.

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This power supply features no ATX cable sheathing, so you may wish to invest a few dollars in some cable management.  For us, plastic twist ties do the trick.

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Features on the Sparkle FSP350-60PN are relatively light.  There are neither serial ATA connectors, nor motherboard monitoring connectors either.  The honeycomb grill on the rear of the unit should provide enough passive airflow, which is a necessity if the 120mm fan is to operate properly.

Wattages

The important thing to realize is the combined wattage on the +3.3V and +5.0V rails.  Even though PCs are ever increasingly dependant on the +12V rail, AMD users need to keep a close eye on the +3.3V power line.  The FSP350 produces a very good 220W on the combined rail.

The Sparkle FSP350-60PN retails for under $50, which makes it a fairly reasonably priced power supply, albeit only 350 watts.

We talked to Enhance a few months ago with thoughts about where PSU technology is headed.  A unique thing about Enhance is that they are one of Intel’s closest development partners, so they always have a plethora of information on hand.  Enhance’s web site has a lot of whitepapers and good information to use when researching a power supply that good for you, even if its not produced by Enhance.

The ENS-0246 comes with very few frills.  The cable is not shielded or sheathed, but does come in a variety of connectors.  Enhance is a very OEM oriented provider, so many of its power supplies have variations on the pin configuration (for different motherboards).  For example, the B version of this power supply has 24 pin ATX while the A and C version have 20 pin ATX cables. 

Wattages

The ENS-0246 460W power supply has a combined power rating of 220W.  The +12V rail is capable of another 180W which leaves this power supply well shy of the advertised 460W.  Our guess is that it is this supply is labeled by its peak power output rather than the actual. 

On the other hand, we do commend Enhance for keeping the combined rail very close to the theoretical limit of where it should be.  It’s unfortunate that the +12V rail was not a little bit higher, otherwise this would have been a very well rounded power supply.

For a 460W unit, the ENS-0246 is moderately priced around $85.  Unfortunately, this is not a 460W power supply, since 460W seems to be more of its peak rating.  More features or higher specifications might have given it the edge.

We saw the elegant and simple TruePower a few months ago, so we were pretty excited to see if Antec had any other products in the PSU industry we could include in our roundup.  The TrueControl 550 is Antec’s highest end product, allowing fan control through a designated 5.25” bay controller.  Memories of our Sound Blaster LiveDrive instantly came to mind.

The controller itself is very utilitarian looking, but it seems to get the job done. For all Antec's worth, they probably could have made the controller look a little more appealing.

Antec clearly spared no expense on the 550W TrueControl, and we noticed this is a very different supply from the 430W TruePower we saw several months ago. Several interesting things caught our attention.  First, this is the only power supply we have seen with an external rear molex connector.  We are not really sure why, but there must be some applications for such a feature.

Also present were black molex connectors.  Almost every power supply we have seen to date uses white or clear molexes.  Besides the 7 standard molex connectors, the unit comes with 2 fan only connectors (also present on the TruePower 430W).  The forward bay allows for control on the internal fans, as well as the fans along these designated fan control rails as well.  A very interesting feature, but it is perhaps limited in usefulness.  A motherboard fan control connector is also included.

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Also, the TrueControl 550 comes with dedicated molexes for fan control. The 5.25" bay is capable of controlling these fans through the power supply. This is defiantly a nice touch since we have previously questioned whether the dedicated fan molexes were worthwhile.

Again, Antec makes the point of demonstrating that the TrueControl 550 has separate lines for each of its 3 main rails. The real element that separates this power supply from the ThermalTake PurePower is the variable voltage on the fan controller. Using the included tool, the unit allows you to modify your voltage settings to adjust within %5 each of the three main rails (+12V, +3.3V, +5V). While this is incredibly useful if you are a die hard overclocker, it can be very hazardous if used incorrectly. For example, underpowering your +12V rail might result in underpowering your P4 or video card, which will eventually damage your components if not careful.

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Wattages

On paper, the theoretical combined 530W maximum impresses us.  Remember, the unique feature about a lot of Antec power supplies is that they have separate rails for each of the three main power lines.  The advertised +12V rail comes in very respectably at 288W. This power supply will work well for the hungriest of AMD or Intel systems. Die hard overclockers will enjoy the control over each rail, which is also offered on the PC Power and Cooling TurboCool. Be warned though, variable pot controls can seriously compromise your system's stability.

Unfortunately, this supply also weighs in as one of our most expensive units.  This is somewhat against the grain of our last Antec power supply which was priced very moderately.  For $130 you get the fan controller, and a lot of extras.  The dedicated power rails are worth it for a serious overclocker, so albeit expensive, the TrueControl 550 still does not disappoint.

We praised the TruePower in our last review because it abided by two fundamental rules; it was efficient and it was cheap.  Antec is large enough to grab good prices from their component makers and thus relay the savings down to their consumers, without sacrificing quality.  Let us hope during the benchmarking of this unit that Antec continues to follow those same rules.  To balance Antec’s representation, we also obtained a TruePower 330W for the roundup. 

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The TruePower 330W is a relatively no thrills power supply, especially when compared to Antec’s 550W TrueControl.  It does come with the standard motherboard monitoring, and the two dedicated fan molexes (controlled automatically by the power supply). However, we are fairly hesitant to use these. The power supply is tucked into its own corner of the case, so we really do not want temperature changes inside the power supply to affect the fan control elsewhere in the case.

Wattages

The TruePower still produces a respectable amount of power on each rail, but not a lot of power on the +12V.  The dedicated +3.3V rail will benefit AMD users, particularly overclockers; but beware of the extremely modest +12V rail.  If you are running a high end video card, or an Intel Pentium 4, this power supply simply will not produce enough juice.

The TruePower 330W is priced around $55, which puts it just a couple bucks under its TruePower 430W cousin.  In our opinion, it would be more cost effective to get the 430W TruePower, which also won our roundup a few months ago.

ThermalTake sent us their PurePower 420W APFC for our last power supply roundup<link>, but it could not keep up with Enermax and Antec.  The 480W PurePower supply is a little more powerful than the previous one we looked at, so we have slightly higher expectations.

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Like Antec’s TrueControl, the ThermalTake PurePower looks like a very different power supply than the original 420W power supply from several months ago.  Also like the TrueControl, this power supply comes with a forward fan control.  There is no ability to control the fan speed of the fans connected to the unit, but the control does allow manipulation of the onboard fans.  Interestingly enough, the PurePower 480W comes with 2 different control panels, (one gold, and one silver). If you happen to prefer one color over another, ThermalTake allows you to choose one instead of another.

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The ThermalTake PurePower 480W includes on SATA connection.  Most serial ATA hard drives come with SATA adaptors anyway, but it is good to see some manufacturers anticipating the mainstream adoption of the technology. We continue to expect more power supplies to come with these connectors.

Wattages

The PurePower 480W wattages are well rounded for either an Intel or AMD system.  One thing to note is that the combined +3.3V/+5.0V wattages are very high at 240W. There is plenty of muscle in this power supply for an AMD or Intel system.

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The ThermalTake PurePower 480W is a moderately priced power supply, about $74. However, considering the 420W PurePower cost $110 last year, we can tell that ThermalTake is making progress in producing a better product for lesser cost.

We had a lot of troubles with Vantec’s last power supply, the Stealth.  We found an error in the production label, which quickly led to a change in all the labeling on all Stealth power supplies.  If anything, we were glad we could make a difference to change a product before it was too late.  Vantec took a lot of our comments to heart, and thus put out a second revision on the Stealth.

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We were told that some of the changes in the power supply included tighter manufacturing specifications and an overall better performing final product.  Vantec also took the liberty of lowering the price of the unit a bit to avoid discouraging system builders.  With those new elements in mind, we set out to try one more time. 

Wattages

Notice that the combined rail on the 520W Stealth is 260 watts.  Interestingly enough, +5.0V rail comes in at 260W.  This is unusually high, and as a result the +3.3V rail is unusually low.  We definitely would not recommend this power supply for AMD system builders, especially overclockers. (Intel system builders will have no problems with wattages).

The saving grace for Vantec comes in the features.  Later in this article we will explain why we are not crazy about the fan control switches, but the cable management, serial ATA connectors, and universal ATX adaptor are great additions. The 24 pin ATX cable will only show full usefulness on Intel server motherboards, but the 24pin to 20pin adaptor is included for standard desktop motherboards as well. The Stealth also comes with 9 standard molexes, which makes sense if this power supply is to target server markets.

By far, the best feature is the external AC plug.  Perhaps it is sort of a nostalgic addition for power supplies, but it definitely is an option that makes sense.  For example, plugging your speakers into the Stealth assures that they are off when your computer is off.  Thus, the speakers do not crackle or produce feedback when shutting down. We don't really recommend connecting a monitor to this outlet, particularly CRTs. You can really damage a CRT by pulling the power on it, so if your computer shuts down unexpectedly a lot, you will have a tough time keeping your CRT in good health.

The Stealth is not a cheap power supply.   Our 520W version costs about $120, which limits their ability to reach out to system builders with shallow pockets. Most of this cost is attributed to the aluminum construction, but other things such as the fan control also kick the price up.

Vantec also gave us the opportunity to take a first look at their Ion PSU.  The Ion is essentially the same as the Stealth but with a steel construction to cut costs down.  Vantec Ions are fairly new to the PC market, so you may have trouble finding them in retail channels still.

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While visiting the Vantec headquarters last month, one of the more interesting things Vantec had to mention to us was their discontent with variable fan controls.  Other power supply companies have also shown their dislike for the feature, since it significantly raises costs, lowers performance and is generally used improperly (if at all).  Further revisions of the Stealth and Ion supplies may drop the fan controller in favor of automatic controls.

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Both the Ion and the Stealth power supplies made a name for themselves but cramming an uncanny amount of connectors onboard.  The Ion comes with 9 standard sized molexes, plus one serial ATA adaptor.  Interestingly enough, the Ion does not come with a universal ATX connector, and just ships with a standard ATX adaptor. 

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Wattages

The Ion has a very low +3.3V rail, like Vantec’s 520W Stealth.  Unfortunately, the Stealth could make up by having a large +12V rail for Intel systems as well.  The Ion will work fine for your basic AMD or Intel system, but those who really push the limit (particularly with a hungry video card) are going to eventually have problems with the low output on this unit.

For $60, the Ion is priced about half that of the Stealth.  The steel construction obviously reduces costs, as well as the elimination of the Universal ATX connector, which we can only guess cuts down on the number of rare components needed for construction.  If anything, the Ion targets the low end system builder market better than its aluminum predecessor.

The most abundant PSU company in our review was TTGI.  Most users have not even heard of TTGI before, let alone SuperFlower.  Interestingly enough, that hardly upsets SuperFlower, who continues to mass produce products under various OEM and discreet labels. Given their unique market position, we took the chance to look at several offerings from TTGI.  Their largest power supply is the 520SS, a 520W offering with 4 fans. 

Again, the variable fan control makes an appearance.  As you will see later in this review, the fan control is the Achilles heel for these power supplies.  TTGI’s good prices and good features make these units very attractive, so performance becomes the most important issue with these units.

Features on the TTGI units are fairly bountiful.  All of the units come in a glossy finish which really would look sharp in a case with windows or other acrylic.  Our unit also came with one quad LED fan.  In our opinion, it probably would have been more appropriate to ship the power supply the same color fan as the finish (or at least just one solid color).  If you are particularly handy, replacing the fan will be no problem. 

Wattages

Like the Vantec Stealth, the TTGI 520SS has an unusually high +5.0V rail. The +3.3V rail is not penalized as much, so we will not criticize them on that.  Do keep in mind that an Athlon 2200+ XP runs on about 60W, so overclockers should consider all the options when looking at these power supplies.

Pricing on the TTGI series is extremely aggressive.  The 520SS runs around $85, much less than the other power supplies running about the same wattages.  (The three fan version runs a little bit less, around $75).

TTGI’s 420SS is virtually identical to the 520SS, but with 2 fans.  It comes with the same glossy finish, plastic ATX sheath, fan control, and 4 color LED fan exhaust. 

Some TTGI units are starting to ship with detachable Serial ATA cables.  Most SATA drives come with these same cables, so purchasing a power supply because it has SATA connectors is not really a smart idea.

Wattages

Statistically, the 420SS is about average.  The +3.3V rail is not sacrificed, and the +5.0V rail is lowered significantly from the 520SS version.  You will loose about 50W on the +12V element, so if you need the extra juice for a video card you may want to rethink dropping down to the 420SS.  TTGI also offers an EPS12 version of the 420SS, which is basically identical to this model but with a 24pin ATX cable.

The selling point in this unit is also its relatively low price. This unit sells for $50, and thus makes it fairly feature filled. The tradeoff in performance comes later, but we will get to that later.

 Our third and final TTGI unit, the 350SS is identical to the dual fan 420SS. 

Wattages

Surprisingly, the +3.3V rail is still identical to the 520SS and the 420SS.  Even more surprising, the +5.0V rail on the 420SS and the 350SS are also identical.  For all practical purposes, this is virtually the 420SS with a different label on it.

You end up saving about $8.00 buying the 350SS instead of the 420SS.  The units are identical anyway, so we really see no reason to go with the 420SS.  Again, for $42 the 350SS is not a horrible investment, but perhaps after you see our benchmark section you will find a different power supply more akin to your tastes.

We received our quad fan Kingwin supply well before the TTGI units had hit American soil.  The unit was well received in the lab, but as we noticed when the TTGI units arrived, practically identical in construction.  TTGI and Kingwin obtain their components from the same manufacturers in Taiwan.

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During the publishing of this article, we stopped at Kingwin to see what new technology they were working on.  One of the more exciting products they were working on was a second generation power supply that contains much different electronic components.  Unfortunately, production samples are still several weeks or months off, so we will not have a review any time soon.

Features on the Kingwin KWI-450 were identical to the TTGI units.  The power supply comes with a sheathed ATX cable, gloss finish, aluminum housing and an LED fan.  Using extra fans provides some relief if one fan were to die.  The idea of “extra” fans has gone a long way for video card manufacturer Albatron, and it is our guess that it will continue to stick around for a while. 

Like the TTGI units, the Kingwin supplies suffered the same unfortunate performance problems with their variable fan controls.  We will discuss in detail these problems later on in the article.

Wattages

The Kingwin KWI-450 puts out 225W on its +3.3V and +5.0V combined rail.  This is about middle of the pack as far as the other power supplies are concerned.  The +5.0V rail still seems unnecessarily high.

At $95, the Kingwin power supply is not the cheapest available, especially compared to the near identical TTGI units.  We have seen vendors put the Kingwin power supplies in Kingwin cases (which are very well received), so they are still prevalent in the market.  Like the TTGI, we thought the Kingwin KWI-450 was a good balance of features and price, but maybe not performance. 

After our last review, we got dozens of emails begging for PCP&C power supplies.  Thankfully, our good friends at Directron.com were able to help us obtain a sample.  Unfortunately, our initial looks at the unit were slightly mixed.

Our largest amazement was that the TurboCool 475 unit had no power switch.  Out of almost 20 represented power supplies, this was the only unit that did not have a simple on/off switch.  The TurboCool 475 was also the loudest power supply we had ever heard, definitely louder than the TTGI or Vantec units on full fan speed.

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On the other hand, the TurboCool 475 does have a few things going for it.  For one, TurboCool is one of the only units we have seen that contains onboard line purification.  This definitely will help our signal and generate great results in our ripple test. To justify the loud fan speed, the TurboCool 475 also stays extremely cool during operation, even under load.

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Albeit subtle, the TurboCool 475 has variable voltage settings inside the unit. The Antec TrueControl puts them on the fan control in the front of the case, which makes it a little more user friendly. PC Power & Cooling makes you void the warranty to get at the variable voltage controls, so its definitely something that is not recommended unless you know exactly what you are doing.

Wattages

The TurboCool has an extremely high +3.3V rail.  This power supply is geared for the AMD system builder, without a doubt.  As a result, the combined +3.3V/+5.0V rail is also quite remarkable; higher than any other power supply we tested. If this is not to your taste you can adjust the voltages on the inside of the unit, although we recommend not voiding the warranty unless you absolutely have no other choice. Remember, playing with the adjustable voltage settings can really mess up your computer. The unit does not come with any ATX sheathing, so you may want to invest in twist ties or some other form of cable management

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When we first obtained this sample, it was priced around $180.  We never really could figure out why it was priced so high, but over the last couple months the price dropped a little to $165.  Even though the TurboCool definitely lacks features, it is the best performer in our benchmark suite.  If you are an AMD builder (or overclocker) and you do not mind the loud fan (and high price), this is the power supply for you.

A great representation of balance between power, price, stability and noise came in the form of Fortron’s FSP400-60PFN power supply.  We were particularly pleased this unit was able to produce a great amount of stability, while keeping noise levels way down.  Most of Fortron’s power supplies carry the same OEM components as Sparkle and Zalman, so many of their products appear identical.

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The unimpressive looking power supply impressed us the minute we turned it because we could not hear it.  Whereas some power supplies emit a slight whine or purr of fans, this power supply was literally inaudible.  Our only complaint is that the ATX cable was not sheathed. Since this is a relatively inexpensive unit, you should invest in some cable management. The power supply does come with a motherboard monitoring cable, and some units ship with Serial ATA adaptors. The unit is also rated with Active PFC.

Wattages

We can see that the combined rail on this power supply is capable of 235W.  This is actually higher than some power supplies in the 500W range.  For AMD users, the FSP400 will work well with AMD processors, since the majority of the power from the unit is coming in on the +3.3V and +5V rails.

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The FSP400-60PFN retails for under $60.  As far as other power supplies go, this is a little higher than what you will pay for a TurboLink or Allied.  On the other hand, this Fortron unit comes with respectable features, and good performance. It should be mentioned that Sparkle (SPI) has an identical unit with the same SKU (FSP400-60PFN) for about the same price.

Zalman’s 400W power supply is almost identical to Fortron’s 400W power supply.  In fact, many of the components are labeled with identical serial numbers.  However, this is not a bad thing at all.  The other Fortron power supply represented in this cross section are of very good quality, and we will see the performance advantages in the benchmark.

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The Zalman 400W APFC power supply abides by the fundamental rule for almost all Zalman products.  It’s quiet and it’s constructed well.  Of course, we wanted the Zalman version of this power supply to come with an ATX sheath, but we think the advantages in performance have proved worthy enough. The unit also comes with Active PFC, motherboard monitoring and Serial ATA adaptors.

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Wattages

The 235W combined rail is identical to the Fortron unit.  Again, this is a respectable range for a 400W power supply, and should perform well for AMD motherboards.

The Zalman 400W is priced very competitively with Sparkle and Fortron’s 400W APFC offerings.  Choosing one would essentially be the same as choosing the other.  We have seen many online vendors carry the ZM400A for around $70, but if you look hard enough you can sometimes find it around same price as its Fortron counterpart.

The EG465 power supply did extremely well in our last power supply roundup.  We have not really seen many other new products from Enermax in the last few months, so we obtained a slightly newer version of the supply we reviewed in our first review instead. 

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From our previous review, you may recall the EG465 PFC’s tight tolerances and excellent features.  The new version sports all of these features, but since the slightly different circuitry warrants a separate benchmark for this PSU.  The variable fan control, motherboard monitoring and copper/rubber ATX sheath are all included on this power supply.  Furthermore, the line we looked at also came in a glossy finish similar to the TTGI units. The unit includes Active PFC as one of its features as well.

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The EG465 also comes with Enermax’s trademark variable fan control on the rear of the unit.  We have not had problems with Enermax’s variable fan controls.  The dial-style fan control assures that the switch can never fall into a halfway position like with Vantec or TTGI.  We will touch more on this issue later.

One annoyance the EG651 and the EG465AX both had was a loud “pop” when the power supply was turned off.  This occurred whether or not the motherboard was on or not. 

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Wattages

This power supply is really a system builder’s treat.  All rails seem to be pretty evenly balanced, with plenty of room on the +3.3V and +12V.  The +12V rating appears to be the peak, however.  A higher combined rail rating would go a long way for this power supply, but we are just nitpicking rather than criticizing these specifications. When talking to Enermax, one of the features they were very proud of was their strict adhesion with the Intel ATX12V 1.2 standard. Of all the power supplies we looked at, the two Enermax units were the only power supplies which displayed this ATX12V 1.2 compliance. We will see this certainly pays off in the performance benchmarks later on.

Unfortunately, with any quality component, the EG465AX-VE is expensive. Most vendors carry the unit for about $85, which prices it aggressively for system builders. We were very pleased with the performance of this unit, as well.

Except for the specifications, the EG651P was very similar to the EG465.  It came with the same glossy finish, copper sheathed ATX cable, and rear variable fan controller.

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Undoubtedly, Enermax has the best power supply cable management capabilities available.  To combat interference, the ATX and +12V cables are copper meshed with rubber sheathing.  This copper shielding extends all the way into the power supply housing, where the rails are also shielded in copper.  It is no wonder why this power supply is also one of the heaviest.

This is the only other power supply in our review to display the ATX12V 1.2 compliance. For those of you not familiar, this is the published standard that assures stability with Intel and AMD systems. This particular standard makes sure the +3.3V rail is not neglected when increasing the wattage on the +12V rail, but also assures tight specifications on the lesser used -5VSB rail. We can see that the specifications on this unit are not skewed only to the +12V rail, so this unit does make sense for an AMD system builder as well.

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Wattages

Specifications alone speak volumes for this power supply.  The +12V rail has an advertised rating of 36A, or 432 watts.  This puts the EG651 way above any other non-Enermax component.  However, since mathematically the power supply can only sustain about 330watts on that rail, the advertised 432 is probably the peak output.  Even at 330W, the EG651 still towers over most power supplies. 

The EG651P-VE is one of the pricier units in our round up.  Most online retailers are carrying this unit for around $135, but with rebates and deals you might get it as low as $120.

We thank MaxPoint for rushing us the two Enermax power supplies to us before the deadline for this article.

To keep our review well rounded, we grabbed a TurboLink 420W PSU from our local computer store.  There is nothing extraordinary about this power supply; we just included it in the roundup to keep a control.  The estimated retail value on this power supply is around $45 (perhaps cheaper if bundled with a case or whiteboxed). It does come with an ATX sheath and motherboard monitoring connector.

Wattages

The TurboLink 420’s specifications struck us as incredibly poor.  Most noticeable is the 185W combined rail specification.  This is actually under the 200W +5V specification so essentially, this TurboLink 420W is never capable of obtaining the listed output.

As we mentioned earlier, this supply is priced around $45, but usually comes bundled with a case anyway.  Chenming and Cheiftec are large bundlers of this power supply.  In our opinion, it would be more beneficial to not get this power supply bundled with the case, and get a Fortron or Sparkle instead.

The Allied power supply was our second control for the experiment.  Another power supply priced around $40, it's usually bundled with other cases.

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Wattages

Allied has the weakest +3.3V rail, even less than the Antec 330W TruePower.  The combined rail is severely underpowered, only putting itself ahead of the TurboLink 420W from the previous page.  Also like the TurboLink power supply, this unit is not capable of the advertised 400W.  The +12V rail and the +3.3V/+5.0 rail (combined) are capable of only 334W total, which put it way under the advertised 400W.

Even though Allied has produced a lot of good power supplies in the past, this is not one of them.  This is basically a 350W power supply with a different label, and even though it retails around $40, the product does not justify the cost.

Below is a look at the wattages for each power supply.  Pay careful attention to the difference between the theoretical and actual combined wattage rails.  The Antec power supplies do not have a combined rail, so their specifications are disregarded.

Wattages below are as claimed by the manufacturers. The combined theoretical rail is simply the sum of the +3.3V and +5.0V rail. This almost always differs from the actual capability of the combined rail, which is also listed. The final item, the advertised total, is the measurement of the whole power supply given by the manufacturer.

Wattages

Below is a table outlining the critical differences between each of these power supplies.  Pay particular attention to price.

One of the more important tests we do when analyzing any type of hardware is thermal testing.  We will analyze internal heatsink temperature in the course of this examination.  We will chart these examinations over 20 minutes to determine which power supplies are actually benefiting from ‘automatic’ fan adjustments.  Temperatures are in degrees Celsius.  The ambient temperature was 21.0C.

Power supplies that did not have automatic settings were tested on the highest setting.  Tests were conducted inside an industry standard Chenming case with no fans running. (Lower temperatures are better)

Heat over Time

All of the power supplies performed well in this category, from the $35 Allied, to the $130 Enermax units.  The best performer was the incredibly loud TurboCool 475, which never made it over 26C. We were a little surprised the Enermax units stayed so hot during the test, but with some tweaking the rear fans could be better manipulated by the motherboard to provide more exhaust.

Hand in hand with the thermal testing of our units is the sonic examination.  Using the same test trials from the previous test, we were able to take a measurement of the noise level.  Obviously, we desire a quieter power supply.

Each sample was taken at a distance of 12” from each supply.  Tests were conducted inside an industry standard Chenming case with no fans running.  Ambient noise was under 21dBA.

Noise

As expected, the Sparkle 120mm power supply had one of the lowest pitch levels (and thus we perceived it to be very quiet).  However, it was the ThermalTake PurePower 480W that really took the prize.  Even with both fans running, it was virtually undetectable.  The Enermax EG465, Zalman 400W and Fortron 400W did very well also. (Keep in mind that the Enermax units were the warmest units in the previous test).

This is kind of a unique test we have worked on for a while.  One of the more important qualities of a power supply is to make sure it does not produce harmful interference to the components.  Perhaps the most sensitive of these components is the memory (video card, RAM, and CPU cache), which is just millions of little transistors locked in an on or off position, held in place only by a delicate balance of electricity. 

The driving theory behind ECC memory is that it corrects errors that occur in memory.  Perhaps a transistor is faulty and flipped for the wrong reason, or a faint electrical signal pulled a transistor into the incorrect position.  While researching this review and others, we have noticed the largest factor for incorrect memory blocks is faulty power supplies. 

How it works:

We started off by modifying MemTest86.  We bumped the delay between tests up to several hours, rather than seconds.  MemTests86 works by writing various patterns into the memory.  After our programmed delay of six hours, the program goes back over the memory and analyzes how many of those bits were flipped out of the original pattern.  Both the memory and motherboard used passed the unmodified MemTest86 without any problems.  

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Not only is this a good measure of shielding on the PSU, but also a good measure of shielding on the motherboard and memory.  However, we used the same motherboard and memory for the entire test.  This way we assure that the small amount of interference coming off the motherboard is consistent with each power supply.  Unfortunately, it took 6 hours to run this test and we ran it three times for each supply to assure accuracy.  On the next page is a table showing the trial data.

Lower error average is better.

Memory Errors over 6 Hours

As we can see, there was a definite separation between different power supplies.  Most notable were the Enermax power supplies, The Fortron and Zalman 400W power supplies, and the TurboCool 475.  All of these kept the memory from producing even 2 faulty flips over a 6 hour period.  This came to almost no surprise to us, since these power supplies were the most shielded and heavily constructed of the bunch.

We took the time to put our power supplies under a multimeter to determine the extreme values of each power supply

We came under a little scrutiny in our last review because we used hard drives to perform our “stress testing.”  Well all you EE folks can eat your hearts out because we built our own resistance platform out of junk found around our lab and the local university basement.  After several power supplies and ECS motherboards later, we came up with something capable of putting our power supplies under 300W of load (60W on the +3.3V, 100W on the +5.0V, and 140W on the +12V rail).

Below is a table of the Voltages we recorded while the system was under load. Using a multimeter we measured the power supplies from the ATX cable. The highest and lowest values demonstrated were recorded.

Measured Voltages

Our table confirms the reverse of the previous interference test. Again, the sturdier constructed power supplies ended up performing with the tigheset specifications.  The TurboCool 475 performed incredibly well; even with our high expectations we could not believe the performance. It is our guess that the PC Power & Cooling engineers really know what they are doing.

An alarming trend we noticed with our roundup was that power supplies with fan controls on the rear of the unit have problems keeping tight tolerances.  We looked into the problem a little more and noticed that while the components on the inside of the unit were of good quality, the fan control switches themselves were not. 

Often the worst cases were fan control power supplies with often poor locking mechanisms.  For example, the TTGI power supplies sometimes let the control switch slip slightly, resulting in a switch that rested half way between “high” and “low”.  As a result, the poor contact produced incredibly awful ripple tests as demonstrated below.

Fan Control out of Place Voltages

Edit:Although these measurements do not show the +12V rail out of specification from the ATX12V 1.2 document, they are much different from the measurements obtained on the previous page. This change warrants some attention, since if unchecked, poor signals will damage your hardware.  Newer motherboards attempt to purify signals coming on the motherboard to prevent catastrophic failure, but voltages over the rails not feeding to the motherboard are very susceptible to failure (this puts a video card or hard drive in serious jeopardy). 

After contacting manufacturers with this information, we got confirmation from companies stating that they planned on dropping the fan control from their power supplies.  Vantec told us that dropping this controller actually lowers their cost significantly, and the savings would be then relayed to the consumer.  Consider how much you actually use the fan control on your power supply (if you have one).  Our opinion is that the tradeoff will be well worth it.

We took a long look at every valuable bit of data we could manage to squeeze out of the power supplies available.  If anything, the most startling data we found in this review was the disappointing problems with some fan controls.  We recommend not buying a power supply with an onboard fan control.

 

Overall, the surprise victors of this roundup were Fortron and Zalman.  Both included virtually identical units in the review and both performed extremely well, especially in the sound tests.  However, since the Fortron units are priced about $20 lower than the Zalman units, we have to give our editor’s choice award to the Fortron. ThermalTake came in very strong, with very low noise and very high stability. The $74 cost is high, but considering the other external fan control power supply costs $60 more, we think the cost is easily justifiable.

As with the last roundup, we were very impressed with the Enermax power supplies.  If their price was not so inhibitive, we would give them a stronger recommendation.  Kudos to Enermax on both of their power supplies represented.

The PC Power & Cooling TurboCool 475 surprised us the most.  It had excellent performance, low heat and relatively good price.  However, when on, this power supply sounds like a train.  One could easily modify the fan, but this would probably throw the unit out of spec and change the performance.

Unfortunately, like with any roundup, we can not include everyone.  Fortunately, our power supply roundups are cumulative.  Next time we do another PSU roundup, we will include the models we have listed here as well as a few other ones.  If you have a particular PSU you would like to see included, feel free to drop a line in our forums so we know for next time!

Once again we would like to thank Directron.com for sponsoring this review and donating the hardware for us to test.  Furthermore, we would like to thank the folks at Maxpoint, Kingwin, Case-Mod.com for providing hardware and testing equipment.