Before performing our overload tests we always like to test first if the over current protection (OCP) circuit is really active and at what level it is configured.

We could increase current on +12 V up to 64 A, above that the power supply shut down. It was great to see that OCP was configured at a value close to the maximum value for +12 V outputs printed on the power supply label (60 A).

So with our load tester pulling 64 A from +12 V, we started increasing current on +5 V and +3.3 V. The maximum we could pull from these two lines with the power supply still working was 10 A each. When we pulled more than that ripple skyrocketed to 275 mV. So the maximum we could pull from this power supply was:

Input	Maximum
+12V1	32 A (384 W)
+12V2	32 A (384 W)
+5V	10 A (50 W)
+3.3 V	1 A (33.3 W)
+5VSB	3 A (15 W)
-12 V	0.8 A (9.6 W)
Total	868 W
% Max Load	115.7%
Room Temp.	50.4º C
PSU Temp.	52.0º C
AC Power	1,079 W
Efficiency	80.4%

This is a really impressive result, because room temperature was at 50º C and efficiency was still above 80%. Noise stayed practically on the same level it was before with the unit delivering 750 W.

Short circuit protection (SCP) worked fine for both +5 V and +12 V lines.

And amazingly the fan of this power supply was really quiet. We could only hear it when the unit was pulling its full 750 W or more. Then it started to make a lot of noise.