I am currently overclocking a 3.00GHz Pentium 4 Northwood to 3.6GHz @ 1.5 volts. I am running an AGP ATI X850 XT @ manufacture settings. The CPU and GPU are both water cooled and usually run at about 30 Celsius with a full load. I am starting to think that the CPU is going out on me? I am a frequent visitor of www.pcpitstop.com and my score is not near as high as it used to be. This system is my brother’s gaming system and he wants me to improve it for him. He does not have the money to go PCI-E right now so I can only upgrade it for him. It is running on an ASUStek P4P800-E which is Socket 478. My question is what are the absolute best CPU and GPU that is fully compatible with the ASUStek P4P800-E?
You won't be able to do much better than a 3.6GHz P4 and X850XT. The best AGP card is the Gainward Bliss 7800GS which is actually a 512MB 24-pipe 7900GT. But it is not available in North America and costs a fortune, making it time to upgrade to PCI-e instead. The 16-pipe reference 7800GS is at best a bit above the X850XT, not worth the upgrade.