Why do you consider that your CPU is bottlenecking your GPU? In which game you had problems and at what settings?
Currently playing Witcher 2 in 720p medium settings and I get like 30-50 fps, problem is it stutters a lot and I feel like it should perform better. Also, I checked out my GPU's manufacturer's page, I dont think it says how many cores it has. Heres the link http://www.gigabyte.com/products/product-page.aspx?pid=4792#ov