babernet_1 :
http://www.tomshardware.com/forum/id-1804779/power-supply-unit-tier-list.html
No, you can see that the Corsair CS series have a lot of ripple on the 12V supply that will reduce the life of the video cards. Try to get a tier 2 A or B level. 650W seems okay.
But in this review http://www.kitguru.net/components/power-supplies/zardon/corsair-cs650m-power-supply-review/7/ is written
"Ripple suppression is held well within industry rated parameters and overall efficiency is very good." so is it really that bad? :O