Ah, yeah, sounds about right. You're using a Phenom II aren't you? I know they aren't all that different from Athlon IIs, and open world games like this are crazy tough on the CPU.
Speaking of which, I might have to reinstall Far Cry 3 to see if it'll run at this resolution. Not freaking likely, but it might be neat to see!
EDIT: Bottoms out at 15FPS, usually gets about 25FPS. Not really playable. Weak. I got jumped by some fools, and didn't really have a chance to take any screenshots, so believe it or not, I won't be posting any screenshots for now.
It was a good game. But after you beat it, nothing was left to do
Phenom II X4 965 C3 Revision 125W Black Edition
6GiB DDR3 1333MHz
ATi Radeon HD 5770 (HiS)
Corsair H50 w/ 2 fans
NZXT Nemesis Elite