koala

Adding a second card would increase fps rates, but x8 will limit it considerably compared to x16. Which graphics driver version are you using? Have you been into the Display options to tweak the settings. Even something basic like changing from Quality to Performance can make a difference. Can you lower the screen resolution, or does that fall under the full-settings issues you mentioned?

Ctrl-Alt-Delete to see how much memory is being used when running your typical applications. If it's getting close to 2gb and starting to use the page file, add more RAM. XP doesn't like more than 3-4gb so unless you're upgrading to Vista, 2gb RAM should be enough. Is it setup as dual channel?

Your PSU has 32A/+12V so should be ok with the 8800GTS. Overclocking will push the PSU and cooling system though. What temps and voltages do you get under stress?


Note: I've removed your link to a games forum. Please don't post spam.