Title says it all. I want to do a little upgrade and want to know what to upgrade first. I would be willing to bet it's my CPU, but wasn't sure. I haven't OCed my CPU mainly due to being concerned about messing something up (never OCed before). I do have a 120mm aftermarket cooler on it and my CPU temps remain pretty low (would have to check on temps at home). My bottom GPU does run about 8 degress warmer than my upper one, but they are both fairly cool also.
Thoughts? Is it my CPU and if so, if I OCed the one I have, would I see substantial gains or should I just spring for a new one? What temps should I look out for when OCing?