Before overloading power supplies we always test first if the over current protection (OCP) circuit is active and at what level it is configured. For this test we installed only cables that were connected to the unit’s +12V3 rail (main motherboard cable and video card auxiliary power cable), turned the unit on with the pattern for our test number five and increased current at +12 V until we saw the unit shutting down. This happened when we tried to pull more than 31 A from +12V3. We think this value is too high, especially when the label says that the limit for each +12 V rail is of 18 A. We prefer to see OCP configured at a level closer to what is printed on the label.

The problem in overloading this unit was ripple and noise. Since when pulling 650 W from it noise was already too high, we could only pull a little bit more without surpassing the 120 mV limit set by the ATX standard. For example, we could pull 815 W from this power supply, but noise level at +12V2 input from our load tester was at 300 mV!

Below you can see the maximum amount of current/power we could pull from this unit with noise levels still inside ATX specs. During this overloading noise level at +12V1 input from our load tester was at 107 mV and at +12V2 input was 121 mV.