If i were to buy an nvidia geforce graphics card, which model should i get?

[tangojoe]

I will be getting AMD Radeon HD 7660D integrated graphics and i want to know at what point do the nvidia geforce series graphics cards get better than these integrated graphics?

 

[Toxophilix]

If we are talking about gaming then this review http://www.anandtech.com/show/6332/amd-trinity-a10-5800k-a8-5600k-review-part-1/2 has quite detailed testing vs (amongst other things) a GT 640. You can see that the GT 640 is in general better, though there are a few cases in which the Trinity product is ahead.