Before overloading power supplies we always test first if the over current protection (OCP) circuit is active and at what level it is configured.

In order to do that we configured our load tester with a low (1 A) current on +12V2 and increased current at +12V1 until the power supply shut down. This happened when we tried to pull more than 22 A from +12V1.

Manufacturers always leave a margin between what is written on the label (17 A in this case) and the level the OCP circuit is really configured (22 A in this case). We always like to see this margin as tight as possible.

Then starting from test five we increased currents on +12 V, +5 V and +3.3 V to the maximum we could with the power supply still running inside ATX specs. The results are below. When we tried to increase one more amp at any output ripple would go to the roof, meaning that the unit stopped working correctly.

Even during this extreme configuration efficiency was above 80%, which is great (consider the results marked as "2", as they are the correct ones, measured with our precision power meter).