[Pirate]

I'm not sure what to suggest, other than I owned a AMD 3400+ with 1.5 gb ram and 6800 graphics card (obviously not the best system!) up until this year and I never had any problems with stuttering, low frame rates yes... but only if I set it to perfect graphics.

One of the things I heard caused stutters on ati cards was having vertical sync enabled - no idea if turning it off will help a nvidia card but you might try setting it to 'forced off' in the control panel and seeing if that solves it?