as far as i know the things which u need to check are:
1.update ur graphics card drivers
2.find the latest patch for it because there are a lot of new patches available out there which are fixing stuttering,low fps,and 'ram not enough' issues
compared to yours, my laptop doesnt stand a chance but even then i had a decent 40+ fps on my laptop with high settings.(mine- 4gb ram,ati 8730m,i5 1.8GHz)