In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce GTX 580 Gainward Phantom 3GB are marginally better than the AMD Radeon HD 7870 DirectCU II 2GB Edition.

The HD 7870 has a 227 MHz higher core clock speed and 16 more Texture Mapping Units than the GTX 580. This results in the HD 7870 providing 30.7 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 HD 7870 has a 227 MHz higher core clock speed than the GTX 580, but the GTX 580 has 16 more Render Output Units than the HD 7870. As a result, the GTX 580 exhibits a 5.3 GPixel/s better Pixel Fill Rate than the HD 7870. However, both GPUs support DirectX 9 or above, and pixeling performance is only really relevant when comparing older cards.

The HD 7870 was released over a year more recently than the GTX 580, and so the HD 7870 is likely to have better driver support, meaning it will be more optimized for running the latest games when compared to the GTX 580.

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 GTX 580 has 1024 MB more video memory than the HD 7870, so is likely to be much better at displaying game textures at higher resolutions. This is supported by the fact that the GTX 580 also has superior memory performance overall.

The GTX 580 has 38.1 GB/sec greater memory bandwidth than the HD 7870, which means that the memory performance of the GTX 580 is noticeably better than the HD 7870.

The Radeon HD 7870 DirectCU II 2GB Edition has 1280 Shader Processing Units and the GeForce GTX 580 Gainward Phantom 3GB has 512. However, the actual shader performance of the HD 7870 is 1099 and the actual shader performance of the GTX 580 is 802. The HD 7870 having 297 better shader performance is not particularly notable, as altogether the GTX 580 performs better when taking into account other relevant data.

The HD 7870 transistor size technology is 12 nm (nanometers) smaller than the GTX 580. This means that the HD 7870 is expected to run slightly cooler and achieve higher clock frequencies than the GTX 580.