Power Supply Roundup - Six PSU's fight to the death

Today Cameron Johnson has posted a power supply roundup comparing some of the latest units from OCZ, Thermaltake, Vantec and Coolermaster. We'll check out the appearance and features of each PSU and then put them up against each other and measure the type of minimum and maximum voltages each is able to deliver with a standard system and then an overclocked system based around an Intel Pentium 4 Prescott processor.
Published Wed, Sep 8 2004 11:00 PM CDT   |   Updated Tue, Apr 7 2020 12:26 PM CDT
Manufacturer: none

Power Supply Roundup - Introduction

IntroductionToday's computers get ever faster. Newer CPU's come in up and over 3GHz. Video cards are now running 500Mhz core and over 1GHz DDR memory speeds. Hard drives increase in size and rev speeds, two or more optical drives come into the system, and fans are all put into the mix to keep it cool. Sounds like a good rig, right? Yes but with the wrong power supply, you can simply find yourself up the creek, without a paddle, so to speak.The power supply unit or PSU as it is known is one of and if not the most overlooked parts of the PC. The power supply provides voltage to all devices inside the case and if you don't have a powerful enough, or good enough quality PSU, you can start experiencing random resets, PC crashing and even in some cases, the entire system dying from over voltage and insufficient voltage regulation - basically a nightmare scenario, so it's crucial you choose the right PSU for your needs.Today we put six PSU's up against each other from OCZ, Thermaltake, Vantec and Coolermaster in varying sizes and features. We'll check out the appearance and features of each PSU and then put them up against each other and measure the type of minimum and maximum voltages each is able to deliver with a standard system and then an overclocked system based around an Intel Pentium 4 Prescott processor which is one of the most power hungry processors currently on the market.

Power Supply Roundup - OCZ Power Stream 520ADJ

OCZ Power Stream 520ADJOCZ has always been one for empowering overclockers - from their memory to their brand of cooling products. We expect something rather impressive from OCZ, and when we get the unit up close, we aren't disappointed.
OCZ has gone a totally different approach with their PSU's. Most we see now are either alloy or black in colour; OCZ has gone for a metallic mirror finish. This actually adds to the appeal of modded cases as the lights reflecting in the case bounces off the PSU and actually reflects more light on the unit.Inside the unit is about 20% bigger than most PSU's and weights about 500 grams more than most, which usually is a good sign in a PSU that high quality parts have been used to produce a much cleaner power source.
While we have seen this feature before, it certainly hasn't had this type of variety. What we are talking about is independently controllable voltage rails. On the back of the PSU just above the power on/off switch are three screw turn potentiometers. These are connected to the +3.3v, +5v and +12v rails of the PSU. Turning them allows you to increase or decrease the voltage up to 5% in either direction. To prevent any damage, three Tricolour LED lights are placed to help you - if the light is green your voltage is within specifications, if the LED goes yellow your rail is under volted and if red you are over volted. This helps as when you place more devices on each rail, you can turn up the voltage should the rail drop in voltage although you will find that you won't really have to for the most part.
OCZ has done a remarkable job on the Power Stream series. Inside everything is clean and well set out. Two extremely large heatsinks create a tunnel for the air to pass through, ensuring good cooling of the voltage regulators which is absolutely critical with an enthusiasts system. To cool the unit, two 80mm thermal controlled fans are used which are located at the back and at the front. The exhaust fan is also LED coloured, so when active the PSU glows green which creates a very stunning visual appeal. The other fan is at the back of the PSU to draw air in from the case and blow it across the heatsinks to create the tunnel effect we talked about just before. As mentioned, these fans are thermally controlled. When the PSU starts to heat up when the PSU is at high voltage the fans start to speed up to a maximum of 4,000 RPM, however, during tests on the actual system, we never managed to make the fans actually speed up (which is a good thing), as our power requirements didn't stress the PSU enough. This wasn't through lack of trying, as you will see, we had many devices connected to simulate what enthusiasts are using today in their systems.
Cable management on the OCZ PSU while good could have been better. First off the ATX power connector is a 24pin version used on most server motherboards and the new Intel 915 and 925 series motherboards. A 24pin to 20pin ATX converter is supplied so you can use the PSU on older 20pin ATX connector motherboards such as Intel Canterwood and Springdale. This cable is sleeved to keep the cables all tidy and out of the way.For server motherboards an 8 pin 12v CPU voltage cable is supplied. Piggybacked off this is the 4 pin power connector used on Pentium 4 and Athlon 64 motherboards which means compatibility is not an issue. These cables aren't sleeved but actually twisted around each other, sleeving would have been preferred.Six standard HDD and two FDD molex power connectors are provided for adding in your drives as well as two serial ATA power headers with the +3.3v line included on them. These cables are also twisted around without any sleeving. The final touch are two HDD molex connectors that have been sleeved as well as shielded with noise filters and resistors to keep the voltage noise away from devices like VGA cards and HDD's that are sensitive to power fluxations and noise on the voltage line which is a very handy feature indeed.SpecificationsOCZ gives the following power specifications:+3.3v Rail: 28A+5v Rail: 40A+12v Rail: 33A-12v Rail: 0.5A-5v Rail: 0.5A+5vSB Rail: 2AMaximum Rated Output: 620 WattsThis is one impressive power supply. OCZ has by far the most powerful 12v rail available. This comes in handy for Prescott CPU's as the Pentium 4 draws its CPU voltage from the 12v rail via the 4 pin connector.

Power Supply Roundup - Thermaltake Polo12

Thermaltake Polo12Thermaltake are more known for their line of cooling products more than anything. Thermaltake have produced some of, if not the best coolers available for the past 3 years or more. I remember slapping on a Golden Orb to an Intel Celeron 300A socket 370 and pushing 450MHz out of it still to this day. It was by far the best cooler available.Now Thermaltake has moved one better into power supply units, let's see if their prowess in coolers has moved to the power supply realm.
Thermaltake has gone the quiet route with their Polo PSU. The unit is solid alloy with a single fan design. There is actually no exhaust fan in this one like traditional designs but simply a grated vent at the back.
Unfortunately we weren't able to remove the cover completely to get a photo of the sinks inside the unit, due to some very short wires on the cooler fan. However, the sinks inside aren't as big as the OCZ series, but look to do a rather good job none the less. To keep things cool a fan on the bottom of the PSU draws air from the case to cool the PSU and the vent design simply allow the heat to escape. A 120mm fan running just over 2,000 RPM keeps things cool and very quiet; in fact this fan was barely audible over the rest of the parts in the case.
On cable management, Thermaltake has one of the best available. All the cables are sleeved and coloured differently for each function.The 20pin ATX has a big black sleeve around it, the 4 pin CPU voltage supply is orange, the SATA power cables are yellow and the molex and FDD are blue. You get two SATA power plugs, nine HDD molex plugs and two FDD plugs which is more than enough for what you are going to put into your PC.SpecificationsThermaltake give a spec sheet as follows:+3.3v Rail: 28A+5v Rail: 40A+12v Rail: 18A-12v Rail: 1A-5v Rail: 0.3A+5vSB Rail: 2AMaximum Rated Output: 410 WattsHere we see that the 3.3v and 5v rails are the same as the OCZ, however, a huge drop in the 12v rail to only 18A. This is what Intel recommends for its Pentium 4's, however, stick some heavy 12v equipment on this baby and you will see overclocking start to fall.

Power Supply Roundup - Vantec VAN-350N

Vantec VAN-350NThe Vantec VAN-350N is the smallest wattage power supply we were sent for this roundup coming in at 350 watts. Most of the latest trends are for 400 watt minimum and pushing into the high 500 watt (and even 600 watt range) in order to keep up with power hungry users who overclock to the extreme.
Vantec has gone for a black hammer-tone finish on its PSU to match the more common case modders preferred PC colour of black - if you have a black case, this baby will fit right in.
Vantec take the same approach to cooling the unit as the Thermaltake Polo12. No rear fan has been placed on this cooler but rather one large 120mm fan sits at the bottom of the PSU and draws air from the inside of the case. This is then blown across the internal components. As the air has no other path to follow but out the rear grill, the air is expelled quietly and efficiently.
Cable management has been one of Vantec's add-on kits for power supplies, so it's without a doubt that we would see Vantec's own PSU with the cable sleeving included. While not colour coded like the Thermaltake PSU, it is all in black to match the PSU. As far as cables go, you get the following:1x 20pin ATX power connector1x 4pin CPU voltage power connector1x 6pin AUX connector (these are now redundant, it is only for legacy this is added)7x 4pin HDD Molex connector with EZ-Grip removal2x 4pin FDD Molex Connector2x SATA Power ConnectorFor the cables Vantec provides enough power ports for a 350 watt PSU to handle, in fact it is the most we have seen on such a small PSU.
Vantec has not only done a good job outside but inside the PSU as well which is where it really counts. Two large gold heatsinks are bolted to the 4 main voltage regulators in order to give as clean a power signal as possible by reducing the heat. While it's not the most aggressive cooling setup there is, it sure does keep a tidy layout with plenty of quality parts.SpecificationsVantec put its specifications for the VAN-350N as follows:+3.3v Rail: 14A+5v Rail: 30A+12v Rail: 15A-12v Rail: 0.8A-5v Rail: 0.5A+5vSB Rail: 3AMaximum Rated Output: 350 WattsOne thing was surprising, while it does lack high amperage on the main lines, its 5VSB line that is used to give standby power to the USB, PS/2 ports for external wakeup is the highest of any PSU, Vantec seems to think that this will be needed, as it does also supply voltage to the memory when in STR mode. In all with the low 15A on the 12v rail I wouldn't recommend this to a Prescott user as it will be extremely taxed under default voltages, let alone an overclocked situation.

Power Supply Roundup - SilenX 350

SilenX 350SilenX is one of the big names in the North American PSU market due to the one thing you might imagine they have going for them. They have one of the quietest PSU's on the market for the consumer PC, just as their name suggests.
SilenX has gone for a no fills approach to the 350 watt model. The case is a standard steel alloy colour, so it really just is your run of the mill looks here. Cooling follows the old standard which is a single 80mm fan placed at the back to extract the heat from the PSU from within the case. No additional fans are used. The 80mm unit is thermally controlled in that it speeds up depending on the temperature inside the PSU casing.
SilenX hasn't put any additional frills on its cables at all either. The unit follows the Intel ATX 2.03 standard with the 20 pin ATX power, 4 pin CPU voltage, six of the 4 pin Molex HDD connectors and two FDD Molex connectors which is quite standard for a 350 watt PSU.
Under the hood is where you start to see why SilenX gets its name. For a 350 watt unit, it has the biggest arrangement of heatsinks, allowing the unit to spread heat into the air much more efficiently, allowing the unit to run the fans at lower speeds, since the components don't heat up nearly as much as traditional units.SpecificationsSilenX give the following specifications of its 350 watt unit:+3.3v Rail: 30A+5v Rail: 36A+12v Rail: 16A-12v Rail: 0.8A-5v Rail: 0.6A+5vSB Rail: 2AMaximum Rated Output: 350 WattsWe can see that SilenX is able to give slightly better results than the Vantec at the same wattage, and with a much more silent feeling to it, SilenX is a slightly better choice at this stage in the game.

Power Supply Roundup - Coolermaster RS-450-ACLY

Coolermaster RS-450-ACLYLike Thermaltake, Coolermaster are more known for their CPU and case cooling products than for its power supply options, but there is always room for improvement, as long as it's done the right way.
The RS-450-ACLY is the latest top of the line model from Coolermaster which is designed in the same black case as the Vantec.
It also has the same identical cooling setup with a single 120mm fan inside using forced ventilation to remove the heat from the back. Using the single 120mm fan at lower RPM allows the unit to push much more air through the PSU casing without having that annoying "Whuuring" sound that comes from other fans.
Cable management is minimal for a top of the line model. Only the 20 pin ATX power connector is sleeved. The rest are plain, however, like the Vantec with its EZ-Grip power connectors, this one features the identical same. In all you have your 20 pin ATX power, 4 pin Voltage power, six blue HDD power EZ-Grip connectors and two FDD connectors, an identical count to the SilenX.
This is definitely a first for a power supply unit. We have a 3.5 inch drive bay mounted wattmeter included in the package. This has a 3 pin plug and connected into a special port on the PSU. This gives the user a readout of how many watts of energy is being drawn off the PSU which allows you to gauge if you are going over the 450 watt maximum which is a good point, however, a voltage and amperage meter would also have been nice to see, as this is where the main problems lie in PSU's - over and under volt and not enough amps.SpecificationsCoolermaster rates the RS-450-ACLY with the following specifications:+3.3v Rail: 20A+5v Rail: 25A+12v Rail: 12A+12v2 Rail: 10A-12v Rail: 1A-5v Rail: 1A+5vSB Rail: 2AMaximum Rated Output: 450 WattsWhat's interesting to note on this unit is the two +12v rails. The 12A rail is connected to the 4 pin voltage supply unit, giving the PSU a dedicated line and amperage for overclocking. While Intel does recommend 18A, this is for PSU's with a single 12V rail; 10A is all that is needed normally for the Pentium 4 Northwood and Prescott processors. This unit should perform quite well in overclocking tests.

Power Supply Roundup - Coolermaster RS-350-AMSA

Coolermaster RS-350-AMSAWe have two Coolermaster units in total for testing; we covered the top of the line, now comes the standard unit without the additional wattage meter.
Coolermaster has made this one more cost effective and simple in design. No fancy cases or special cooling on this one. The unit is the standard Steel Alloy grey with the 80mm fan at the back. This fan is always on, with no active control for slowing the fan.
Cable management like on the top of the line remains the same, as does the mount of connectors, however, the EZ-Grip system is removed and standard plugs are used.SpecificationsCoolermaster rate the RS-350-AMSA with the following:+3.3v Rail: 28A+5v Rail: 28A+12v Rail: 15A-12v Rail: 1A-5v Rail: 1A+5vSB Rail: 2AMaximum Rated Output: 350 WattsOn this model there is only a single 12v rail of 15A. In all I wouldn't recommend this to a Prescott user, as about 12A would be used under overclocking conditions.

Power Supply Roundup - Testing

In order to simulate a more common test system, we used the following components.Test System SetupProcessor: Intel Pentium 4 3.2GHz E (800MHz FSB) (Supplied by Spectrum Communications)Memory: 2x 512MB OCZ DDR-533 (Supplied by OCZ)Hard Disk: 2x Maxtor Maxline III 250GB 7,200 RPM SATAGraphics Card: ATI Radeon 9800XT Optical Drive: 1x LG GSA-4040B DVD-RW and 1x MSI DR8A DVD-RWSound Card: Sound Blaster AudigyOperating System: Microsoft Windows XP Professional SP1The Intel Pentium 4 Prescott processor was chosen as it is the most power hungry CPU currently available. While we could have put this onto a DDR-2 platform with the Pentium 4 560, DDR is still more common and draws more power than DDR-2. As most of these PSU's are designed for the 478 series Pentium 4 and AMD Athlon 64, this is what we are going with for testing.Voltage ReadoutFor this test we connected separate Multimeters with recording capabilities to each of the voltage rails. This gave us the ability to record the highest and lowest fluxuations in the voltage lines.We tested the system at both standard clock speeds and then overclocking the CPU from 3.2GHz up to 3.6GHz (1.55v on the CPU core, 3.2v on the memory, 1.65v on the AGP bus) we also overclocked the video card as well to increase the amount of energy drawn.As a final note, most manufacturers claim a leeway of +/- 5% of any given output level. Using this as a common ground, we should end up with rail voltage levels of 3.135-3.465v on the 3.3v rail, 4.75-5.25v on the 5v rail and 11.4-12.6v on the 12v rail. Keep this in mind when we go through the numbers below. Higher values can be beneficial, lower values bear watching.Maximum Recorded - Standard Clock Speeds
Here we see the OCZ Power Stream come out on top.Maximum Recorded - Overclocked Speeds
Here we see that OCZ has allowed a stable voltage system as it didn't go under specified voltages at all. In fact, it was the cleanest we have seen and we didn't even need to adjust the power through the three turn dials.Minimum Recorded - Standard Clock Speeds
Again OCZ stays on top. This was the minimum recorded voltages, this happened at start-up of the operating system.Minimum Recorded - Overclocked Speeds
Again the OCZ Power Stream stays stable no matter what you throw at it.

Power Supply Roundup - Final Thoughts

Final ThoughtsOCZ Power StreamOCZ is one of the world's best memory manufacturers for overclockers and their impressive Power Stream PSU is something to complement that. It is designed from the ground up with independent rails which means when you load up one, the others are not affected. It has the ability to tweak the 3.3v, 5v and 12v rails independent of each other, so only the one that needs the voltage adjustment gets it.Along with this it has the 24 pin ATX power connector for next generation LGA775 motherboards as well as supporting server classed chassis with its 8 pin voltage power connector. The only downside was that the cables weren't all sleeved, but the twisted lines do make up for it a bit.In all this PSU was way beyond what we expected and receives a rating of 9.5 out of 10 TweakTown's "MUST HAVE" Editors Choice Award
Thermaltake Polo12Thermaltake has this time done a good job on the Polo12. Its voltages were stable at standard and overclocked speeds. It didn't fail under load like some of their others have done in the past, and with a reasonably good price tag it would make a good alternative for the OCZ Power Stream.Thermaltake receives a rating of 8 out of 10Vantec VAN-350NThe Vantec PSU, while looking good, didn't seem to have the extra bit that we normally see from their PSU's. While it did perform well, it didn't seem to have that extra "meat". When trying to run a Prescott system on the PSU, it caused the unit to run quite hot, especially with overclocking. We wouldn't recommend doing it for long periods of time. Vantec receives a rating of 7 out of 10SilenXThe SilenX PSU was the worst of the units we tested. While we cannot go as far as saying don't buy this PSU, it is best kept for the Northwood CPU, as it randomly reset on the Prescott unit. In all if you want a silent, cheap PSU for a Northwood, this PSU is one to look out for. SilenX receives a rating of 7 out of 10Coolermaster AS-450The Coolermaster 450 watt PSU was a superb unit. Its dual 12v rails gave stability to the Prescott CPU, and allowed a flawless overclock. It has enough power to spare for the many other devices that you will want to attach, including the GeForce 6800 Ultra series graphics cards without having to worry about going over the limit. The wattage meter was also a great feature, especially when you want to keep track of the voltage situation.The Coolermaster AS-450 PSU receives a rating of 9 out of 10 and TweakTown's "MUST HAVE" Best Value Award
Coolermaster AS-350The 350 watt Coolermaster PSU was similar to the SilenX in that it is more suited to working with the older Northwood based Pentium 4 processors. While it is okay for Prescott at standard clock speeds, when overclocking the 450 watt version is the better option.Coolermaster AS-350 receives a rating of 7.5 out of 10

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