I already had an EVGA GeForce GTX 680, and I just got another one for cheap (friend sold his PC). The problem is that my CPU is an Intel i5-2500 (not K), and I don't know if it'll cause a bottleneck in regards to gaming. If I'm installing two GTX 680's, I want to get as much performance out of them as I can. I planned on eventually upgrading to the i7-3770K, but should I spend the $300 to upgrade now or am I okay for awhile?
EDIT: I also want to add that I'm only gaming on one monitor at 1920x1080 resolution.
No there is no bottleneck until maybe 1600p where the 2500 likely will start bottlenecking. Even at 1200p that 2500 should keep up (many games don't even use HT or more than 4 cores). To be very honest stock up on a 3570K or 2500K (They are literally i7 2600Ks/3770Ks without HT) and OC them to whatever is stable.
You should be fine if you not playing CPU heavy games, usually ones designed to be PC only. you can increase the turbo multiplier on that cpu a bit if you have not already which should help some. You could even increase the BLCK by a little bit (maybe not even worth the hassle). I would spend the money on as awesome monitor so you can actually use those two cards for something other than crysis 3 !