Originally Posted by Atham
AX850 is good. Also Seasonic X 850 is also good. Both of the PSUs are by Seasonic I think.
That's true, they are both Seasonic models, but the Seasonic versions has less ripples and a bit higher efficiency across all power loads but the difference is small 2-4%.
Go with the Seasonic if you want the best performance you can get, they both have similar noise profiles (fanless in low load and pretty damn quiet). If you want to sleeve them yourself, then go with the Seasonic still. The Corsair model has a mixed bunch of cables (has flat and sleeved cables) while the Seasonic are all sleeved so sleeving would be much easier on the Seasonic. The two PSU's are so similar that they have almost (not sure on this) the same cable layout.
Both PSU's can also handle 1000W easy =)