I have a MSI KA780g motherboard. I was wondering what the best GPU is that would work with this motherboard. I have 8gb ram, 550w psu, and i am using an amd phenom ii x4 920 cpu. I currently have an ATi Radeon 4670HD, doesnt seem to be doing the trick. When i look at the booklet i was given, it says i can use either nvidia or radeon. 9800 nvidia and 4850 hd is the highest of both brands. I feel like i can get more but i am not sure, help me out!