The GTX560ti has a TDP of 170W. Two in SLI will use twice that, so for easy math lets say 350W. Toss in a 95W quad core CPU and another 50W for board and drives, and you'll need a total of 500W(ish) on the 12V rail. A PSU that can do 42A will just clear this mark, get one that can do 45A for any headroom you want. Also remember that you'll need four 6pin PCIe plugs.
I think you are cutting it close with that PSU. It is not only the rating but the quality as well. If I am not mistaken, few PSU's actually put out over 80 percent constantly.
I am using an Antec 650W New PS with a single 560Ti and I will be thinking of getting something beefier if I go SLI.
Really is cutting it close but should work. The system in my signature rarely reaches above 650W while gaming with GPUs at full load. The 560s require a bit less power. Definitely will be operating near peak under heavy load.
While Rosewill is usually junk, if I remember correctly the green series is ok. You have enough power but you are correct that you lack the plugs. One plug maybe, but having to use two should cause you concern. The manufacturer didn't intend for four to be used for a reason.
Well I think i was going cheap on my system. I decided to go with the Corsair Professional Series HX750 80 Plus Silver Certified.
It doesnt make sense to put all my new components at risk on the cheap PSU that came with the bundle I bought from newegg. I can use this one as a back up or see if I can get some money back via ebay. Thanks for the help guys. I will install it along with a 2nd 560 ti and an upgraded cpu cooler.
Installed the power supply and both 560ti cards, nice supply but hard to hide the cables for the graphics cards. Fired up the Witcher 2 with same settings and found about a 15-20 bump on FPS. I was able to turn on SSOA and make the line of distance to "far" and maintain over 60 fps.
I am not sure SLI worth the jump so much in my case. I can return the card I bought to newegg and get $200 back. Not sure what to do....it is nice to know that I can probably run any game for a while now but......