Not long ago, a 300W PSU was considered overkill for a PC. Times have changed, quite drastically I should add, and nowadays, 300W should be considered the very minimum. Why is that? Well, for one thing, a large number of users are running dual hard drives, a high speed processor, a blazing video card, and probably two optical drives, a sound card and a half dozen case fans. Power has to come from somewhere, and simply put, even a lesser 300W PSU will have some problems with this.

Of course, more is not always better. During my research for the right PSU for our Radeon 9700, I've stumbled across several forum threads where people were suffering instabilities, even with 400W PSUs. Quality my friends, it's all about quality. Just because it has a 400W sticker slapped on the box does not mean it will perform as well as a brand name 350W.

Finally, there's the subject of noise and cooling. Many of todays power supplies are relatively quiet when compared to the older PSUs of yesterday. This is probably not a huge concern for users who are used to four 6000rpm case fans running, but for people where silence is golden, a noisy PSU is something they'll prefer avoiding. Cooling is also a job a PSU takes upon itself, as most of them are designed to help exhaust some of the air out of the rear of the case.

Click To Enlarge

Thermaltake, well known for their cooling products, have expanded their product line, and other than adding cases to their inventory, they are also producing power supplies. As we've just mentioned, power, quality, noise and cooling are the four top selling points of power supplies. Will the do the job? That's what we're here to find out today...

Specifications

P/N W0009R
Maximum Power: 420 Watts
Switches: ATX Logic on-off additional power rocker switch (115/230 Volt selector switch)
Fan: Dual Fan, Ball Bearing, Temp. Auto Control
1300 rpm at 25°C ~
2400 rpm at 80°C
P. G. Signal: 100-500ms
Over Voltage Protection recycle AC to reset:
+5V trip point < +6.8V
+3.3V trip point < +4.5V
+12V trip point <+15.6V
Intel Pentium 4 Compliant

DIMENSIONS
Unit Size: 15cm(L)x14cm(W)x8.6cm(H)
Net Weight: 2.5kg

INPUT
Input Voltage: 115 VAC / 230 VAC
Input Frequency Range: 47-63 Hz
Input Current: 10.0A (Measuring Range 90-132Vrms), 5.0A (Measuring Range 180-264Vrms)
Hold-up Time > 16ms at Full Load
Efficiency > 65%

I was a little surprised that the PSU Thermaltake ships is a little, shall we say, generic in appearance. Given their "cooling" reputation, I half expected to see an aluminum encased PSU. There isn't much included in the package, other than the PSU, the power cable and the screws. The box was pretty beaten up during shipping (good job Fedex!), but the PSU itself was undamaged.

Although the review unit is a 420W PSU, you'll have to remember that the 420W is its maximum output. Even so, many manufacturers can claim "x" number of watts, but what you will want to be concerned with is the combined output of the +5v and +3.3v rails, which is what items such as your CPU, AGP/PCI cards, and memory needs, as well as anything plugged into the floppy power connection. If possible, you'll want at least 200W combined. The Purepower has 220W, which is pretty good. The +12v rails are for the 4 pin molex connections, which plugs into pretty much everything, and the Purepower provides 216W for your fans and drives.

The Silent Purepower is an Active PFC unit. What is that exactly? Power Factor Correction (PFC) essentially means less power is lost, or as , leaked. The result is more constant power that is less likely to fluctuate under load.

Many loads are highly inductive, such a lightly loaded motors and illumination transformers and ballasts. You may want to correct the power factor by adding parallel capacitors. You can also add series capacitors to "remove" the effect of leakage inductance that limits the output current.

Non-PFC offers around 0.5~0.6 PF (Power Frequency), 40%~50% power lost.

Active PFC provides more efficient PF(Power Frequency), 0.95~0.99, it means only 1%~5% power has gone.

Steady power is essential for enthusiasts as the last thing they need while running an overclocked, RAID system is a power drain when opening their web browser. Another preventive feature is over voltage protection. Although it will not replace a UPS, if there is a sudden spike in voltage, the PSU will shut itself off to protect itself (and in the long run, your components).

Click To Enlarge

One of the selling points of this unit is both the cooling and being quiet. Both of these goals are achieved by a couple of temperature controlled fans. I am a little wary about the maximum speed though. According to specifications, the fans speed up to 2400rpm at 80C. Unless I'm mistaken, that's friggen hot. Granted, inside a PSU does get toasty under load, but unless your PC is located next to your furnace, I seriously doubt temperatures will get that high. Even if it did, I think you have more serious problems to address than to complain about the noise from the PSU fans.

The fans are ball bearing fans, which are usually better quality than sleeve bearing. Despite having two fans, when I was running some benchmarks for a heatsink review, the fans did not make much noise at all. You'll have to remember that in most cases, most PSUs shouldn't make much noise, and those that do are either really cheap (as in quality), or they're about to break down. Compared to the Enermax I was using before, the difference wasn't that noticable at all.

Click To Enlarge

The Thermaltake Silent Purepower comes with plenty of molex connections. There are 9 standard 4-pin connections, as well as three floppy connections. In case you're wondering why you'd need three, soundcards, such as the Audigy Platinums require a connection, as does the Radeon 9700.

Click To Enlarge

Naturally, being an ATX compliant power supply, you have your standard ATX power connection, as well as the P4 connection if you need it. Like the Enermax, Thermaltake has a nice mesh sleeve over the main power cord. A nice touch would have been to put the sleeve on all the connections, but I guess that's hoping for too much. Also pictured is the fan detection connection if you want to monitor the fan speeds of the PSU.

Click To Enlarge

Inside the PSU are a variety of heatsinks, PCB boards and capacitors. I'm not a PSU expert, so I couldn't begin to tell you what to look for. What I can tell you is that a PSU is very dangerous if you are thinking of doing any modifications. This is especially important if the PSU was plugged in recently, as the residual charge could kill you. Ouch!

Click To Enlarge

Installation was problem free. Depending on your case, many power supplies with dual fans, such as the Enermax, can sometimes prove to be problematic to install. At least for our Lian-Li, the Enermax required removal of the bottom fan grill to install. Not so with the Thermaltake, and it installed without the need of modification.

Testing

AMD Athlon XP 1700+ @ 1.660 GHz
MSI KT3 Ultra2
2 x 256MB Crucial PC2700 DDR
ATi Radeon 9700 Pro
2 x Maxtor Diamondmax 80GB, RAID-0
Sound Blaster Audigy, with Live! Drive
3Com 10/100 NIC
Plextor 24/10/32X
AOpen 16X DVD
Vantec Aeroflow w/TMD Fan
3 x 80mm Sunon 50CFM fans

I would imagine that the above system would illustrate a fairly common power user setup. Every item above requires power, and stability is key when you're running that much hardware. The comparison power supply will be the Enermax Whisper 430W PSU. Unfortunently, I don't have a Voltmeter handy, so I'll be demonstrating load in the BIOS, as well as with MBM.

Enermax (left), Thermaltake (right)

Both power supplies do alright at the +5v rail, but the Thermaltake performs better at the +12v rail. The Enermax is within 5% though, which is within specifications, but if you're paranoid about hard drive failures, you will want this number as as close to (or above) +12v as possible.

Enermax

The Enermax above is a little low on the +3.3, +5, and +12v. In its defence, a lot of power supplies don't reach these rails, so as long as it's not more than 5%, it's ok really.

Thermaltake

Notice that the +3.3v is reached, as is the +12v. They are short on the +5v, but our Radeon 9700 is rock solid nevertheless.

Cooling Performance

Honestly, cooling performance was something of a non-event. System temperatures with the Enermax hover at around 34C. With the Thermaltake, it was 35C. You'll have to keep in mind that the fans in the Thermaltake are 80mm, whereas the Enermax are 92mm. I also don't think the Thermaltake fans were spinning at full speed, but at 35C, they shouldn't need to. I should also mention again that noise levels between the two PSUs were comparible.

Final Words

I was quite surprised to see the Thermaltake do so well. Considering this is this first crack at power supplies, they obviously spent the time to make a good PSU. It could be a little flashier I suppose (i.e. aluminum), but that would have added to the cost.

At 420W, this particular Silent Purepower should be highly considered if you run a fair amount of hardware in your PC. There are lower watt models available, but in my opinion, everyone should consider 400W as a minimum now. The power supply handled our test platform without incident. It's been powering our rig for well over a month now, 24/7, and so far, so good. With over voltage protection, and Power Factor Correction, you can sleep easy knowing your peripherals won't get zapped.

Cooling and noise performance was pretty much what we expected. Our case fans easily overpowered any noise the PSU would make. As for cooling, it performed on par with Enermax PSU.

Pricing is comparable to to Enermax PSUs, but given the results of the tests today, I'm going to have to give the Purepower the nod.

Pros: 420W, good performance on all 3 rails, decent cooling and low noise.

Cons: One fan monitoring cable.

Bottom Line: If you're an overclocker, and/or stack your PC with everything, that 300W Athlon approved PSU circa 1999 is not going to cut it anymore. You're going to want something that is capable of putting out the juice you need, and to supply quality power. The Thermaltake Silent Purepower gets my recommendation without hesitation.

If you have any comments, be sure to hit us up in our forums.

HOME