In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce 8800 GTS EVGA SSC 640MB Edition are noticeably better than the Nvidia GeForce GT 640.

The GeForce GT 640 has a 326 MHz higher core clock speed and 8 more Texture Mapping Units than the 8800 GTS. This results in the GeForce GT 640 providing 15.1 GTexel/s better texturing performance. This still holds weight but shader performance is generally more relevant, particularly since both of these GPUs support at least DirectX 10.

The GeForce GT 640 has a 326 MHz higher core clock speed but 4 fewer Render Output Units than the 8800 GTS. The lower ROP count doesn't matter, though, as altogether the GeForce GT 640 manages to provide 2.9 GPixel/s better pixeling performance. However, both GPUs support DirectX 9 or above, and pixeling performance is only really relevant when comparing older cards.

The GeForce GT 640 was released over three years more recently than the 8800 GTS, and so the GeForce GT 640 is likely to have far better driver support, meaning it will be much more optimized and ultimately superior to the 8800 GTS when running the latest games.

The GeForce GT 640 has 1408 MB more video memory than the 8800 GTS, so is likely to be much better at displaying game textures at higher resolutions. However, overall, the 8800 GTS has superior memory performance.

The 8800 GTS has 43.5 GB/sec greater memory bandwidth than the GeForce GT 640, which means that the memory performance of the 8800 GTS is noticeably better than the GeForce GT 640.

The GeForce 8800 GTS EVGA SSC 640MB Edition has 96 Shader Processing Units and the GeForce GT 640 has 384. However, the actual shader performance of the 8800 GTS is 138 and the actual shader performance of the GeForce GT 640 is 346. The GeForce GT 640 having 208 better shader performance is not particularly notable, as altogether the 8800 GTS performs better when taking into account other relevant data.

The GeForce GT 640 transistor size technology is 62 nm (nanometers) smaller than the 8800 GTS. This means that the GeForce GT 640 is expected to run massively cooler and achieve higher clock frequencies than the 8800 GTS.

The GeForce 8800 GTS EVGA SSC 640MB Edition requires 143 Watts to run and the GeForce GT 640 requires 65 Watts. We would recommend a PSU with at least 400 Watts for the 8800 GTS and a PSU with at least 350 Watts for the GeForce GT 640. The 8800 GTS requires 78 Watts more than the GeForce GT 640 to run. The difference is significant enough that the 8800 GTS may have an adverse affect on your yearly electricity bills in comparison to the GeForce GT 640.