Efficiency and Power Factor
The power factor is 98 to 99% through most of the load range, just as you can expect from active PFC.
As for the efficiency factor, I want to give you some clarifications as to the 80+Platinum requirements for 115V and 230V power mains.
On one hand, the PSU exceeds the 80+Platinum specs for 115V mains (90%, 92% and 89% efficiency at loads of 20%, 50% and 100%) but on the other hand, it falls short of the 80+Platinum requirements for 230V mains by about 1% in my test which was carried out in a 220V power grid (the PSU notched 94%, by the way, but only at 390 watts rather than at 50% load).
However, the 80+ standard only certifies PSUs for redundant, data center applications when it comes to 230V mains. Such PSUs are very different from ordinary PSUs for desktop PCs and workstations which are only 80+ certified for 115V mains.
A PSU should get somewhat more efficient after switching from 115V to 230V mains because of the reduced current strength. The Seasonic SS-1000XP Active PFC F3 gives us a good example as it is about 1% more efficient than the 80+Platinum requirements for 115V mains in this test.
Thus, it is a true 80+Platinum product even though its efficiency may seem to fall short of the 80+Platinum requirements for 230V mains (which are not applicable to it, as I’ve explained above).
+5V Standby Source
The standby voltage is very stable.
The Seasonic SS-1000XP Active PFC F3 is a real engineering masterpiece with its all-modular design, quiet operation up to very high loads, very high efficiency, stable voltages, low voltage ripple, good compatibility with UPSes and 7-year warranty. The only “problem” I can think of is that its box lacks a handle. Moreover, it may be pretty expensive, which is, actually justified by all means.
The only things I’d love to see improved are the cables: I wish it had flexible flat cables (like the FSP Aurum or Enhance EPS-1280GB4 units) and less aggressive behavior of the fan under high loads (I would rather have the fan keep the temperature at the same level instead of lowering it). On the other hand, I have to admit that the PSU’s current cables and acoustic performance are close to perfect already.
In fact, the Seasonic SS-1000XP Active PFC F3 seems to be the best PSU we’ve ever tested in our labs. We’ve seen quiet, high-wattage or user-friendly PSUs but none of them could offer all of these in a single package! Therefore, we are proud to award this product our Editor’s Choice title: