It certainly can. Some single graphics cards can produce higher quality images than certain dual video cards, though. There are a lot of factors going into it. Mainly what you already have to work with and what your budget is.
What i wanted to ask, if i installed another one of the same cards 8600GTS, and enable SLI will i be able to run newer games like the upcoming Final Fantasy 14 game? If not what should i look into to renovate or upgrade my pc.
Processor: Intel(R) Core(TM)2 Duo CPU E6750 @2.66GHz
Memory: 2044MB RAM
DurectX Version: DirectX11