As mentioned, yes, but if you want to consider dual cards in the future, and since you are in the market to buy now, I would expand that just a little bit. Power supplies normally live beyond several builds and it would be worth the time now to consider your future usage/options. Personally I wouldnt build a gaming system with less than 650watts from a quality PSU manufacturer. That PSU will likely survive 2-3 rebuilds depending on your rate of upgrades/rebuilds. It is normally a few dollars now, to increase a substantial percentage. Normally paying itself in the long run because power supplies run more efficiently when they are less loaded, than when they are nearing 75% or their maximum capacity. Over the years, this would net any savings possibly lost on the initial purchase.
Yes I do understand that but unfortunately I am stuck with a Dell right now, so this is just an upgrade to that. The 6770 was OEM. As a side note, I assume the 560 Ti 488 core GPU will be compatible with my system?