I have just built a system.
Xeon quad core (LGA1366) engineering sample (70$ on ebay for a new one from a good seller)
4GB RAM (Kingston HyperX Blu, will upgrade soon)
500GB Seagate hard drive
650W PSU (Cooler Master)
HAF 912 case
Zotac GT 520
What GPU should I upgrade to? I would like to get it at the NCIX yearly half off sale, and want to spend no more than 160$. I know this is a bit premature, but at this point, I'm just looking for ideas. Should I get a 600 series GPU, or use an older but cheaper 500 series one? Should I go to AMD instead?