Thermaltake make great PSUs! They combine great build quality with high power with excellent efficiency. This PSU is no different! Sporting a max power output of 1275W it is also 80+ Platinum certified which makes it up to 94% efficient!
I have added some specs below but check the source for much more detail.
Basically what this means is that you should be able to run 4 way SLI or 4 way Crossfire setups with no problems!
I had to do some research to see whether this was the only white PSU on the market and it isn't. NZXT have one but it is only a 1000W model which makes this PSU not only one of the most powerful on the market, but the most powerful white PSU available!
See the official specification page for more details.