AnandTech: Ultra High-End PSU Roundup

Introduction

As PC systems are demanding more and more power, the power supply manufacturers are reacting by releasing units rated for higher power output. We can all thank NVIDIA and ATI, among others, for this trend, as we have seen an escalation in ridiculously high demands for power supplies with the latest graphics chips. That this power is in most cases unnecessary should be clear to everyone who owns such a card or wants to buy one.

One reason such requirements are overkill is that the resolution you are running is largely responsible for higher GPU requirements, which in turn leads to more power hungry systems. If you are running a top-end video card (or two) at just 1280x1024, much of the performance potential is going to waste. Still, multiple GPUs under load will still require a beefy PSU, generally starting at 400W and going up from there, depending on the rest of the system. If you're running a 30" LCD on the other hand - particularly with overclocking - we have seen power requirements break 600W in worst-case scenarios.

For those people who still believe the marketing hype - or for the extremely rare exceptions where you might actually run a system that needs 800W or more of power on a regular basis (feel free to let us know what you're doing that requires that much power!) - if you're thinking about buying this kind of power supply we are presenting today three of the highest rated power supplies on the market. In increasing overall wattage rankings, we start with the PC Power & Cooling Turbo Cool 1200W. Next is the Cooler Master Real Power Pro 1250W. Finally, we have the new ITZ 1300W PSU from Tagan.

As usual we are testing with our Chroma programmable loads to fully load each rail to a specific amount. This is important to get truly accurate results and not merely approximate values. The tests are conducted in two different temperature environments. One is normal room temperature of 25-26°C, while the second environment goes from room temperature and increases steadily up to 50°C. Especially during the higher temperatures we will see how good the power supplies are and what they're really made of. Components inside will perform much worse at higher temperatures, but we expect any good quality PSU to deal with such test conditions without failing.

On the DC output graphics we show the range of highest and lowest voltage. There is usually a bit of variance, particularly with multiple 12V rails, but with a PSU roundup we want to convey as much information as possible without simply bombarding our readers with graphs and charts. In essence, we will show the voltage range on each rail at various load points. This is especially easier to read and understand if you have more than four 12V rails since we will show them all in one graph together.

Note: If you would like to know more about our testing methodology, equipment, and environment, please read our PSU testing overview.

In a change from previous testing, we have added an additional 10% on the highest load to see how the units perform at overload levels. This test will be performed in all future reviews. The overload test will be performed at room temperature, but experience shows that many units can stand the overload in room temperature but will show problems at higher temperatures when overloaded. To verify this, we will also test in our stress 50°C environment. We don't want to be too cruel with the power supplies, so we will make sure we keep the ambient temperature at 50°C in the worst-case overload testing. Only the best PSUs will survive this sort of testing... but then anyone looking at 1200W+ PSUs is probably interested in exactly that sort of unit.