Enermax Platimax 850W Semi Modular Power Supply Review

Our cross loading procedure is designed to rigorously test the stability of the main two rail combinations. We push the maximum rated current and wattage through the 12 volt rail(s), and then through the 3.3 and 5 volt rails combined, and see if the power supply is capable of delivering its specification for those. However, meeting the specification is not enough, the power supply must also maintain strong voltage regulation and noise/ripple to have “passed the cross load test. 

The cross load test is a “worst case scenario” for the two main power delivery rail mechanisms (12v and 3.3+5v) and so the power supply will always deliver slightly lower than realistic/expected results. However, this is not necessarily a realistic test and it is just a case of pushing a power supply’s rails right to their rated limits to see how well they can hold up.

12 Volt Cross Loading

Voltage regulation was exceptional given the high cross loading. All rails maintained within 1% of their rated voltages. A truly impressive showing from the Enermax Platimax 850W PSU.

Ripple and noise was also very strong given the magnitude of the 12 volt load.

5 and 3.3 Volt Cross Loading

Voltage regulation at 5 and 3.3 volt cross load was exceptionally tight and only the 5vsb slacked a bit which is totally acceptable given that in a real usage scenario your PC would never have high load whilst being in standby at the same time!

Noise and ripple on both the 3.3 volt and 5 volt rails was around 10-20 millivolts which isn’t exactly close to 0 but by any standards is still very strong indeed and will keep all your components running smoothly and safely.