Since you just got the GTX460, I would go for a quick cheap upgrade. As of now your Athlon 255 is a bottleneck for the GTX460. A tricore athlon would be enough to get rid of the bottleneck. Check your bios if you have core "unlock" feature or ACC advanced clock calibration. If the board can unlock, look for a used Athlon X3 455 Rana (90% chance to unlock to a stable quadcore). It probably goes for around $20. If you want a sure quadcore, just look for a used Phenom X4 955.
8/9/15 at 2:21pm