Result Summary

The Corsair SF750 joins our ranks of PSUs which successfully completed our test sequence in elevated ambient temperature between 5 and 110 % of the PSU's rated power output. The unit's high level performance looks very good. In terms of the acoustic performance, the PSU remained completely passive util we hit the 50 % load mark. As the PSU uses a smaller fan, the initial expectations were that the fan might become fairly loud at higher loads. But the end result proved otherwise. At 38.6 dBA at full load and 42.2 dBA at 110 % we can't really call the PSU inaudible, but the sound level is far from annoying.

Where the results could be better is the power factor correction at lower loads. And so could be the efficiency levels at the very lowest loads.



At 5 % and 10 % load the unit's efficiency reaches almost 85 %, which is by no means low, but for 80 Plus Platinum units we are getting used to >87 % and >90 % efficiencies respectively. The good news is that from 20 % load we see the efficiency shoot to over 92.7 % and remain over 92 % up until the 80 % load, peaking at 93.86 % and maintaining a 90.7 % efficiency even in the overload test. While technically we did not hit the magical 94 % mark, it's still among one of the better results we have seen for the recently tested 80 Plus Platinum units.

Voltage Regulation

Voltage regulation is where the Corsair SF750 shines. We're used to seeing very good +12 V regulation, but with the SF750 we can confidently say that this continues for the +3.3 and +5 V rails as well.

Ripple

Ideally you want the DC voltage delivered by your power supply to be a completely flat line when looking through an oscilloscope. However, due to the switching nature of ATX power supplies and the less than ideal real world behavior of all the components involved, we get very small fluctuations in output voltage known as ripple and noise. The ATX spec allows for ripple of up to 120 mV for the +12 V rail and 50 mV for the minor rails.


The ripple is well controlled overall. While we have seen lower ripple numbers, at under 42 mV for the +12 V rail for the overload test we are well within the ATX limits. An oscillogram of the 110% load test can be seen below.

Short Circuit Protection

Short circuit protection is one of the most fundamental and important protections for a power supply. If a short circuit is detected on any rails, the PSU should turn off to prevent damage to itself and other components.


SCP worked as expected with the unit.