In terms of overall gaming performance, the graphical capabilities of the AMD Radeon R7 240 v2 2GB are marginally better than the Nvidia GeForce GT 640.

The GeForce GT 640 has a 172 MHz higher core clock speed and 12 more Texture Mapping Units than the R7 240. This results in the GeForce GT 640 providing 14.3 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 172 MHz higher core clock speed and 8 more Render Output Units than the R7 240. This results in the GeForce GT 640 providing 8.6 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 R7 240 was released over a year more recently than the GeForce GT 640, and so the R7 240 is likely to have better driver support, meaning it will be more optimized for running the latest games when compared to the GeForce GT 640.

The GeForce GT 640 and the Radeon R7 240 v2 2GB have the same amount of video memory, but are likely to provide slightly different experiences when displaying game textures at high resolutions.

The R7 240 has 43.5 GB/sec greater memory bandwidth than the GeForce GT 640, which means that the memory performance of the R7 240 is noticeably better than the GeForce GT 640.

The GeForce GT 640 has 384 Shader Processing Units and the Radeon R7 240 v2 2GB has 320. However, the actual shader performance of the GeForce GT 640 is 346 and the actual shader performance of the R7 240 is 212. The GeForce GT 640 having 134 better shader performance is not particularly notable, as altogether the R7 240 performs better when taking into account other relevant data.

The GeForce GT 640 requires 65 Watts to run and the Radeon R7 240 v2 2GB requires 30 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 R7 240. The GeForce GT 640 requires 35 Watts more than the R7 240 to run. The difference is significant enough that the GeForce GT 640 may have a slight adverse affect on your yearly electricity bills in comparison to the R7 240.