I was using a GT 240 with 1 GB of DDR 3 RAM. I was not sure if buying the GTX 650 Ti with 2GB of DDR 5 RAM for $170.00 would be worth it. All I can say is that the GTX 650 Ti exceeded my expectations and it can out put to 4 monitors. I imagine the standard GTX 650 would have worked great as well. I am writing this to let people know you can get some decent real-time with a cheap $85.00 CUDA enabled video card but spending $170.00 is well worth it. I think the cheap GT 640 cards can also support 4 monitors although I do not see any of them with the 4 ports on them. Below is the card I bought.