So after the upgrade I can now play crysis/warhead on my projector at 720p with every setting on 'vhigh/enthusiast', it looks awesome and its as smooth as silk! So thanks for all the advice everyone

My spec is now:
intel core2duo e6600 + ac7 cooler (still at stock speeds)
gigabyte 965 ds3p
4gb ocz platinum 6400 ddr2
evga gtx 260
bluegears b-enspirer soundcard
samsung spinpoint f1 1tb hdd
nzxt hush case
corsair 650W tx series
dell 2407 monitor
optoma hd65 projector