If that i5 doesn't do any more than "turboboost," get a different one, or a different MoBo. You want full OC'ing ability. Most i5 and i7 chips will make at least 4GHz without breaking a major sweat. Need proper cooling, though, which you don't have. Which brings me to...
Crap cooler. Never a stock cooler if you want to OC. Get something like a CORSAIR Hydro Series H80.
What's the timing specs on that memory? Can't evaluate system performance without knowing the memory timing. 8GB is fine, though. More is better, of course.
Insufficient power supply. 750W is absolute minimum. Over 1000W for that CPU and GPU is overkill. I run an i7-950 OC to 4.2GHz and a 660Ti with a 750W without problems, but if I started having problems, the PS is the first replacement I will make.
recommend 2ea WD 2TB Black drives or at least 2ea. WD 1TB Black drives. One for the sole purpose of backup and system image. Don't skimp here.
Yes on Win8 64bit. (Not Win8 RT, of course, because that's not "real" windows. Don't get burned; know the difference.)
Who's building this thing? You? Who spec'ed it?
Rock on!
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