Well, when running virtual instruments on a stand-alone program with my midi keyboard, or in a sequencer program, the CPU pretty much gets abused (I'm talking around 60% used alone in that, which causes some problems). And Core Duo is way too expensive (I think the best one is around 1,000AUD and the lowest one is around 500AUD, whereas the P4 is only 130AUD).

RAM is a pretty big factor in a lot of things that I do, mainly among music production and gaming. Whenever loading instruments or samples, I always get RAM error saying I don't have enough. So I think I might just chuck out my two sticks of different speed RAM and may as well get 2GB for the hell of it.

Plus, I have to run most games in 1680x1050 just so I can utilize my new 21" screen.

Edit: Just saying in general, that I don't really feel like upgrading this computer to duo 2 core or anything like that, seeing as I can't even use PCIe and would probably need a better power supply or something.