In terms of overall gaming performance, the graphical capabilities of the AMD Radeon HD 7970 PowerColor LCS 3GB Edition are significantly better than the AMD Radeon HD 7850 XFX Ultra OC Edition.

The HD 7970 has a 75 MHz higher core clock speed and 64 more Texture Mapping Units than the HD 7850. This results in the HD 7970 providing 72 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 HD 7970 has a 75 MHz higher core clock speed than the HD 7850 and the same number of Render Output Units. This results in the HD 7970 providing 2.4 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 HD 7970, and so they are likely to have similar driver support for optimizing performance when running the latest games.

The HD 7970 has 2048 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 HD 7970 also has superior memory performance overall.

The HD 7970 has 120 GB/sec greater memory bandwidth than the HD 7850, which means that the memory performance of the HD 7970 is massively better than the HD 7850.

The Radeon HD 7970 PowerColor LCS 3GB Edition has 2048 Shader Processing Units and the Radeon HD 7850 XFX Ultra OC Edition has 1024. However, the actual shader performance of the HD 7970 is 1828 and the actual shader performance of the HD 7850 is 849. The HD 7970 having 979 better shader performance and an altogether better performance when taking into account other relevant data means that the HD 7970 delivers a massively smoother and more efficient experience when processing graphical data than the HD 7850.

The Radeon HD 7970 PowerColor LCS 3GB Edition requires 250 Watts to run but there is no entry for the Radeon HD 7850 XFX Ultra OC Edition. We would recommend a PSU with at least 650 Watts for the HD 7970 and a PSU with at least 500 Watts for the HD 7850. The HD 7970 has been recommended a PSU with 150 Watts more than the HD 7850. The difference is significant enough that the HD 7970 may have an adverse affect on your yearly electricity bills in comparison to the HD 7850.