My brother is coming over next weekend - he has my old 3600+ @ 2.something. I can get a 5600+ for $50.99 at Newegg, and I may replace his 7800GT with the 4650 I have kicking around. He runs 1024x768 on a 15" LCD, so it's not exactly needing SLI GTX 285's to run most stuff.

Do you think it's worth $50 for that upgrade, or should I tell him to start saving for an entirely new build? The rest of the system is old but not that bad..160Gb + 400Gb HD, 4Gb DDR2..

If he really is planning on sticking with a 15" monitor for a while longer, then that cpu upgrade is probably the best choice. He gains a few hundred mhz with double the L2 cache.

Conversely, If he's tired of 1024x768 and plans to get a new monitor soonish, then I would suggest he start saving towards a new cpu/mobo/gpu.

He can't really get a job with his school schedule (high school + winter + Maine + no car), so he's pretty much stuck. I may just encourage him to come up with what he can and maybe build him a new one for his b'day next fall.