system
A chat on subreddit /r/pcmasterrace
human
Untrue. My SLi GTX 460 setup performed absolutely great. I got double the FPS in many games, it was only AAA titles that got the performance boost, but it was those that needed it. There were some games that didn't play nice with it but they were few and far between. It did have issues with micro stutter though.
gpt
You're talking average fps, but SLI/CFX were notorious for terrible microstuttering. Even after years of updates and improvements, it still wasn't really solved.