XFX XPS-650W Power Supply Review

Testing:

Efficiency and Power Factor:

The efficiency and power factor are well within the requirements of the ATX12V V2.2 specification, so an overall pass in this section. The power supply does however fail to meet the requirements of its claimed 80 Plus Bronze certification following the OCC power supply testing methodology. Bronze level certification requires levels of 82%, 85% and 82% efficiency at 20%, 50% and 100% loading with a power factor of 0.9 or greater at 50% load. Power factor levels are fine but the power supply fails to reach 82% efficiency at 100% (actually 93%) loading with an AC input of 110VAC. It is presumed the 80 Plus certification is for 115VAC, the standard for most if not all power supplies, but there is a problem when searching for the certificate on the 80 Plus Org website, it isn't listed under XFX.

AC Ripple On DC Outputs:

I have consistently found the AC ripple levels on the DC rails to be more or less equal with a 110VAC or 230VAC mains supply. The results given below are for 230VAC only, but I will continue to check the levels at 110VAC during testing and publish them below if there are any significant differences.

AC Ripple On +3V3 Rail at 230VAC

Oscilloscope settings: Amplitude = 5mv/div, Timebase = 5uS/div

AC Ripple On +5V0 Rail at 230VAC

Oscilloscope settings: Amplitude = 5mv/div, Timebase = 5uS/div

AC Ripple On +12V Rail at 230VAC

Oscilloscope settings: Amplitude = 10mv/div, Timebase = 5uS/div

AC Ripple On -12V Rail at 230VAC

Oscilloscope settings: Amplitude = 10mv/div, Timebase = 5uS/div

AC Ripple On +5VSB Rail at 230VAC

Oscilloscope settings: Amplitude = 5mv/div, Timebase = 5uS/div

The AC ripple/noise levels on the XFX XXX Edition 650W rails are a little higher than some other power supplies in this class, but they still fall under the ATX12V V2.2 permitted levels.