I am soon going to be ordering parts for my new computer and just wanted to make sure that a 650w psu will be enough to run my 6970, i seen radeon suggesting you need at least that, but would it be a good idea to go above it, or will it be enough? Also if i plain to add another 6970 at some point what type of psu would i need and would it be a good idea to get it now instead?