In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce GT 640 are noticeably better than the AMD Radeon HD 7660D + 7670 Dual.

The HD 7660D has no core clock speed set, so any comparison between Texture and Pixel Fill Rates is not currently possible.

The GeForce GT 640 was released less than a year after the HD 7660D, and so they are likely to have similar driver support for optimizing performance when running the latest games.

The GeForce GT 640 has 1024 MB more video memory than the HD 7660D, so is likely to be much better at displaying game textures at higher resolutions. However, overall, the HD 7660D has superior memory performance.

The HD 7660D has 0.3 GB/sec greater memory bandwidth than the GeForce GT 640, which means that the memory performance of the HD 7660D is marginally better than the GeForce GT 640.

The GeForce GT 640 has 384 Shader Processing Units and the Radeon HD 7660D + 7670 Dual has 760. However, the actual shader performance of the GeForce GT 640 is 346 and the actual shader performance of the HD 7660D is 0. The GeForce GT 640 having 346 better shader performance and an altogether better performance when taking into account other relevant data means that the GeForce GT 640 delivers a noticeably smoother and more efficient experience when processing graphical data than the HD 7660D.

The GeForce GT 640 requires 65 Watts to run but there is no entry for the Radeon HD 7660D + 7670 Dual. We would recommend a PSU with at least 350 Watts for the GeForce GT 640.