The best CPU my motherboard will take is a Pentium D 960, 3.6 Ghz. What's the best GPU I should bother getting? If you could, give a reasonable option and an option erring on the side of bottle necking/paying too much/maximum juice. Drink it up.
Thats not your motherboard, thats your chipset, Now i believe that cpu to be socket 775 so the mobo should support some better chips, core 2 duo, core 2 quad, Although if it is an old intel board it may not
Right thats a 775 motherboard so you should be able to fit at least a low end Pentium Duel Core. Just out of interest, what do you use your pc for? Because you may just be better off selling it and upgrading