Overload Tests

After these tests we tried to pull even more power from Corsair HX620W. Below you can see the maximum amount of power we could extract from this unit keeping it working with its voltages and electrical noise level within the proper working range. During this test room temperature was of 48° C and the power supply was working at 58° C.

Input Maximum
+12V1 28 A (336 W)
+12V2 27 A (324 W)
+5V 8 A (40 W)
+3.3 V 8 A (26.4 W)
+5VSB 3 A (15 W)
-12 V 0.8 A (9.6 W)
Total 746 W
% Max Load 120%
AC Power 901 W
Efficiency 82.8%

Under this extreme condition noise level continued very low, at 43 mV on +12V1 and 38.2 mV on +12V2, as you can see below. This is really good.

Corsair HX620WFigure 26: Noise level at +12V1 input from the load tester at 750 W.

Corsair HX620WFigure 27: Noise level at +12V2 input from the load tester at 750 W.

We tried to push this unit above 750 W but the unit started working outside its specs, or the ripple all of the sudden would do far above 120 mV or the voltages would drop to values outside the working range.

We didn’t see over power protection or over current protection in action, as the power supply turned on with values that were making it to work outside its specs. For testing over current protection (OCP) we pulled 33 A from EPS12V (the maximum we could configure using our load tester) putting all other connectors to pull a low value (5 A) and the power supply worked just fine, and the power supply didn’t shut down as it should. At least it didn’t burn, which is another good thing about this power supply.

Short-circuit protection worked just fine.

During our tests 3, 4 and 5 the power supply generated a not so loud high pitch noise.

Another great feature about this power supply is its fan. When the power supply is cool, it runs very slowly, making almost no noise. But even when it was operating at full load and the fun spinning at its full speed, noise level was very low, making this power supply one of the most silent power supplies we have reviewed to date.


Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.