The 650 can just
barely do it @ 1920x1200 (34 FPS), but not totally maxed out (only using FXAA).
http://images.anandtech.com/graphs/graph6359/50580.png
Keep in mind that they're using a 3960X there (and OC'd, at that), so with the 6100, you're definitively looking at a few less FPS, at the very least.
Lowering the resolution would help the 650 significantly, but it would show the shortcomings of the 6100 even more. You're kind of damned either way, there.
I would say if you can get 35 FPS average, close to maxed out @ 1080p, you'll be lucky. Probably closer to something in the mid 20's.