Performance and Cooling. Asus GTX 680 DirectCU II Top 2GB SLI or Asus GTX 680 DirectCU II 4GB SLI. Which of these 680's would be the better choice, 2GB's seemed like enough but the 4GB model seems like it would perform better as I am going to use it on 3 monitors. But by the looks of it the 4GB models' cooling did not seem to be as good as the 2GB. It's great that it has dual slots instead of the triple slot but it does not matter to me. The question is which would perform better on a triple screen setup and would have the better cooling?