well your cpu's fine, and the rams fine! 2gb :thumbsup:
however i think 16x12 could be a bit much for the 6800gt, specially on big maps with all the features on. also depending how old that version of FRAPS is, that could be the culprit
i remember FRAPS used to Impede performance, ie having it on made the FPS slower, i experienced it with Splinter Cell Chaos Theory, i would only get 24Fps max, untill i turned it off. then it became noticably smoother.
if you wanna play at 16x12, then id turn the AA off, and leave AF on. and also dont run FRAPS
bring down the console in the game, which is this button ` (the one to the left of the number 1) for me. then type
renderer.drawfps 1
i think thats it, that will make the game report its own FPS as red digits in the top left