Cooler Master 550W "Real Power" Power Supply

How We Test Power Supplies:

In order to thoroughly test a power supply we have built a special rig that is capable of dynamic load levels on each rail. A short article covering our power supply testing methodology in detail can be found here. Please read over the guide if you haven't already, you might just learn a thing or two. Simply plugging a power supply into a regular PC for "testing" is not accurate by any means, nor can any useful numbers be extracted by testing that way.

Also worth reading is our power supply primer article titled, Powering Your PC: Truths and Misconceptions - A Guide To Power Supplies, which covers how power supplies work in great detail.

If you have read the power supply testing article, you know that we publish four (4) groups of numbers for each power supply to give a simplified overall representation that can be compared to other power supplies. Many other load ranges are tested (but not published unless there is a serious problem) to ensure voltage levels remain within ATX12V specifications. I like to refer to it as "working the switchboard" since it involves flipping lots of switches tied to resistors on each rail to achieve various loads. Unfortunately we can't always dial in exact maximum numbers because of the fixed levels of resistance, but load levels we test are often far in excess of any load a regular PC will create.

Cross Regulation Information:

Seeing as how this power supply is an EPS12V / ATX12V hybrid, the cross regulation graph is a little different from the "generic" ATX12V guide. Cooler Master was kind enough to provide some extra information with the power supply, and it just so happened the cross regulation data was one of them. I went ahead and graphed the various load levels that were tested to give a better idea of the range of actual testing.

The graph below illustrates the generic 450W cross regulation design as shown in the ATX12V guidelines. Achieving maximum 12V power usage with the Cooler Master PSU (graphed above) doesn't mean having to sacrifice 3.3V & 5V output (unlike the design graphed below).