In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce GTX 670 PNY 2GB Edition are marginally better than the AMD Radeon HD 7950 VTX3D 3GB Boost X-Edition.

The GTX 670 has a 35 MHz higher core clock speed and the same number of Texture Mapping Units as the HD 7950. This results in the GTX 670 providing 3.9 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 GTX 670 has a 35 MHz higher core clock speed than the HD 7950 and the same number of Render Output Units. This results in the GTX 670 providing 1.1 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 HD 7950 was released less than a year after the GTX 670, and so they are likely to have similar driver support for optimizing performance when running the latest games.

Both GPUs exhibit very powerful performance, so it probably isn't worth upgrading from one to the other, as both are capable of running even the most demanding games at the highest settings.

The HD 7950 has 1024 MB more video memory than the GTX 670, so is likely to be much better at displaying game textures at higher resolutions. This is supported by the fact that the HD 7950 also has superior memory performance overall.

The HD 7950 has 47.7 GB/sec greater memory bandwidth than the GTX 670, which means that the memory performance of the HD 7950 is noticeably better than the GTX 670.

The Radeon HD 7950 VTX3D 3GB Boost X-Edition has 1792 Shader Processing Units and the GeForce GTX 670 PNY 2GB Edition has 1344. However, the actual shader performance of the HD 7950 is 1417 and the actual shader performance of the GTX 670 is 1317. The HD 7950 having 100 better shader performance and an altogether better performance when taking into account other relevant data means that the HD 7950 delivers a noticeably smoother and more efficient experience when processing graphical data than the GTX 670.

The GeForce GTX 670 PNY 2GB Edition requires 170 Watts to run but there is no entry for the HD 7950. We would recommend a PSU with at least 500 Watts for the HD 7950 and a PSU with at least 500 Watts for the GTX 670. The two GPUs have been recommended a PSU with the same amount of wattage. As such, there is no need to worry about which will more significantly affect your yearly electricity bills.