Skyrim played on med settings 720p on a AMD 5650m back when I had a studio 17, forget mods on that GPU though. without mods, at that res and med details and low FXAA etc it barely handled 30fps most of the time..
I never tried it again until I recently got a 7970m, with an i7 it flew maxed out 1080p. I've since modded the heck out of Skyrim and still it pulls over 45fps in many areas, until I went a bit OTT and killed it, installed a few too many mods and it plummeted to under 30fps, below 30fps and I think its unplayable, 25fps bare min...
But out of the box, 7970m with an i7 and that game simply few.