Re: EVGA GeForce GTX 260 C216 Superclocked or Vanilla GTX 275?
If you were going to have only one fan, I'd definitely say the back, but you really need two fans. You need one in the front to pull the cooler air into the case and blow over your components and then an exhaust fan to then suck the hot air out of the case.
Even if you had to get an 80mm in the front, that would be fine. If you have two different sized fans, I would have the larger one in the back and the smaller one in the front. I think you'll see your temps drop by around 5 degrees or more with two fans.
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