Virtual-Hideout posted a review on the Ultra X2 750W Extreme Edition ATX Power Supply

You may notice in the test graph that the PF rating is rather low or high, depending on how you look at it. The .82% is above the normal reading that is given from Ultra, and will be what the average user will see due to the fact that I'm only pulling roughly 350W. My system setup didn't even dent the capabilities of the Ultra X2 750W Extreme Edition, but users with a higher demand for the wattage will see a much more efficient reading overall. You may also notice that I don't have any voltage readings of the rails fluctuating; well, any minor fluctuating is normal whether at idle or at full load.

Ultra X2 750W Extreme Edition ATX Power Supply Review