See my signature for my bench scores on stock clocks. On BF2 I get about 33fps on medium settings, 800x600 60Hz and AA set at 2x . If you max out all the settings it plays at about 16fps average which isnt that great, but who cares ? You dont need to run these high settings. On Low settings with no AA, it runs at about 50-60fps. Its perfectly acceptable for use with BF2, I recently got it and Im very pleased.
...btw....get a desk, unless you want 3rd degree burns on your thighs. The area where the ram is gets like super hot