In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce GTX 680 Asus OC 2GB Edition are significantly better than the AMD Radeon HD 7850 XFX Ultra OC Edition.

The GTX 680 has a 83 MHz higher core clock speed and 64 more Texture Mapping Units than the HD 7850. This results in the GTX 680 providing 73 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 680 has a 83 MHz higher core clock speed than the HD 7850 and the same number of Render Output Units. This results in the GTX 680 providing 2.7 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 7850 was released less than a year after the GTX 680, and so they are likely to have similar driver support for optimizing performance when running the latest games.

The GTX 680 has 1024 MB more video memory than the HD 7850, so is likely to be much better at displaying game textures at higher resolutions. This is supported by the fact that the GTX 680 also has superior memory performance overall.

The GTX 680 has 38.7 GB/sec greater memory bandwidth than the HD 7850, which means that the memory performance of the GTX 680 is noticeably better than the HD 7850.

The Radeon HD 7850 XFX Ultra OC Edition has 1024 Shader Processing Units and the GeForce GTX 680 Asus OC 2GB Edition has 1536. However, the actual shader performance of the HD 7850 is 849 and the actual shader performance of the GTX 680 is 1746. The GTX 680 having 897 better shader performance and an altogether better performance when taking into account other relevant data means that the GTX 680 delivers a massively smoother and more efficient experience when processing graphical data than the HD 7850.

We would recommend a PSU with at least 500 Watts for the HD 7850.