I was planing on adding another gpu soon but wasn't sure that a 750w psu had the power to run 2 670s.
here are my specs
1) Asus p8Z77-v lga motherboard.
2) EVGA gtx 670 FTW edition.
3) Corsair Hx series 750w psu.
4) intel i5-3570k.
5) Cooler Master HAF 932 case
6) Noctua NH-D14 heat sink.
7) G.skills ripjaws 8gb ram.
9) Asus dvd burner.
10) Samsung 120gb ssd
11) Western Digital 1tb hard drive
also i don't think this really maters but i installed some case leds as well. not sure on their power usage but i can't see them being alot.
Overclocking. i might do a little but nothing to serious.
That is about it I'm planing on adding the other 670 FTW this month thanks for the help.
That Corsair unit runs over 60A on the 12v rail, so you shouldn't have any problems. The top figure I've seen listed for SLI 670s under load is just under 600 watts, and that was with a highly overclocked 6-core CPU and both 670s running substantial overclocks as well (1098 core / 1176 boost).
Yes, it will do just fine, that psu can handle ~900w power drawn without worries, two 670 gtx and the rest you'll have doesn't even reach 750w.
Tom's hardware 2000$ build has that psu with two 7970 which draws even more power than two 670 gtx :