In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce GT 640 are noticeably better than the AMD Radeon HD 6670 v2.

The GeForce GT 640 has a 102 MHz higher core clock speed and 8 more Texture Mapping Units than the HD 6670. This results in the GeForce GT 640 providing 9.7 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 102 MHz higher core clock speed and 8 more Render Output Units than the HD 6670. This results in the GeForce GT 640 providing 8 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 a year more recently than the HD 6670, and so the GeForce GT 640 is likely to have better driver support, meaning it will be more optimized for running the latest games when compared to the HD 6670.

The GeForce GT 640 and the Radeon HD 6670 v2 have the same amount of video memory, but are likely to provide slightly different experiences when displaying game textures at high resolutions.

The GeForce GT 640 has 2.9 GB/sec greater memory bandwidth than the HD 6670, which means that the memory performance of the GeForce GT 640 is marginally better than the HD 6670.

The GeForce GT 640 has 384 Shader Processing Units and the Radeon HD 6670 v2 has 480. However, the actual shader performance of the GeForce GT 640 is 346 and the actual shader performance of the HD 6670 is 192. The GeForce GT 640 having 154 better shader performance and an altogether better performance when taking into account other relevant data means that the GeForce GT 640 delivers a slightly smoother and more efficient experience when processing graphical data than the HD 6670.

The GeForce GT 640 transistor size technology is 12 nm (nanometers) smaller than the HD 6670. This means that the GeForce GT 640 is expected to run slightly cooler and achieve higher clock frequencies than the HD 6670.

The GeForce GT 640 requires 65 Watts to run and the Radeon HD 6670 v2 requires 66 Watts. We would recommend a PSU with at least 350 Watts for the GeForce GT 640 and a PSU with at least 400 Watts for the HD 6670. The HD 6670 requires 1 Watts more than the GeForce GT 640 to run. The difference is not significant enough for the HD 6670 to have a noticeably larger impact on your yearly electricity bills than the GeForce GT 640.