lolklolkgf :
I'm wondering if I would gain more graphical performance by just getting another gtx 660 ti or replacing my current mobo and proccesor with an Asus Z77 motherboard and an i5 3570k. Replacing the processor and motherboard would cost considerably more.
Current Specs:
Intel Core i3 550 3.85ghz OCed
Corsair Vengeance 1600mhz ram
Intel p7p55d-e motherboard
OCZ Agility 3 SSD 60gb
160gb sata 1 hdd
GTX 660 Ti (EVGA)
750W PSU
Depends entirely on what games and applications you use. With the higher end games and applications which require more CPU you would be at an advantage to have a better CPU. I'm not entirely sure how the i3 550 performs, all I know is that it has 2 cores and 4 threads. The i5 3570k is a good processor, you would not regret buying it either way. Adding another 660 Ti will give you more FPS up until a point where the CPU is bottleknecking. Buying an i5 3570k will help you push a little further with your signle GPU, but not sure how much of advantage you would have. Put it this way, I went from a Q6600 with GTX 560 Ti to a i7 3770k. 10 FPS improvement in Crysis 2.
Just shop around a little, look at reviews and benchmarks and you'll see the difference. Personally I'd take the CPU and motherboard upgrade. Does your current single GPU serve its purpose?