In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce GTX 770 SLI are noticeably better than the AMD Radeon R9 270X Crossfire.

The GTX 770 has a 46 MHz higher core clock speed and 96 more Texture Mapping Units than the R9 270X. This results in the GTX 770 providing 107.8 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 770 has a 46 MHz higher core clock speed than the R9 270X and the same number of Render Output Units. This results in the GTX 770 providing 2.9 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 R9 270X was released less than a year after the GTX 770, 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 Radeon R9 270X Crossfire and the GeForce GTX 770 SLI have the same amount of video memory, but are likely to provide slightly different experiences when displaying game textures at high resolutions.

The GTX 770 has 90.1 GB/sec greater memory bandwidth than the R9 270X, which means that the memory performance of the GTX 770 is massively better than the R9 270X.

The Radeon R9 270X Crossfire has 2560 Shader Processing Units and the GeForce GTX 770 SLI has 3072. However, the actual shader performance of the R9 270X is 2285 and the actual shader performance of the GTX 770 is 3333. The GTX 770 having 1048 better shader performance and an altogether better performance when taking into account other relevant data means that the GTX 770 delivers a massively smoother and more efficient experience when processing graphical data than the R9 270X.

The Radeon R9 270X Crossfire requires 360 Watts to run and the GeForce GTX 770 SLI requires 400 Watts. We would recommend a PSU with at least 750 Watts for the R9 270X and a PSU with at least 750 Watts for the GTX 770. The GTX 770 requires 40 Watts more than the R9 270X to run. The difference is significant enough that the GTX 770 may have a slight adverse affect on your yearly electricity bills in comparison to the R9 270X.