Crashes/slowdowns...ect?

[Sobe]

Hey all, I recently got into beta and am enjoying it a lot. But i have been noticing some things that really get in my way, and i would like to see if others have these problems too.
When say im flying in a reaver, and its in a crowded area , i might make a sharp turn and bam, i crash to desktop. Or when im just in a crowded area on foot, i might just crash to desktop.
Not just that but i have a good dsl connection, 512 ram, pentium4 1.7 processor, and a g4mx440. Now i know my graphic card sucks, but would the massive lag in hot action zones be from it? I mean, wouldn't 512 ram help a lot? If i get a radeon 9700 pro with this same system, will the slow downs be gone pretty much completly? Or do i need a faster processor to support a 9700 pro. Thanks