In terms of overall gaming performance, the graphical capabilities of the AMD Radeon R9 280X are very slightly better than the Nvidia GeForce GTX 960 2GB.
The GTX 960 has a 277 MHz higher core clock speed than the Radeon R9 280X, but the Radeon R9 280X has 64 more Texture Mapping Units than the GTX 960. As a result, the Radeon R9 280X exhibits a 36.7 GTexel/s better Texture Fill Rate than the GTX 960. This still holds weight but shader performance is generally more relevant, particularly since both of these GPUs support at least DirectX 10.
The GTX 960 has a 277 MHz higher core clock speed than the Radeon R9 280X and the same number of Render Output Units. This results in the GTX 960 providing 8.9 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 GTX 960 was released over a year more recently than the Radeon R9 280X, and so the GTX 960 is likely to have better driver support, meaning it will be more optimized for 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 280X has 1024 MB more video memory than the GTX 960, so is likely to be much better at displaying game textures at higher resolutions. This is supported by the fact that the Radeon R9 280X also has superior memory performance overall.
The Radeon R9 280X has 175.8 GB/sec greater memory bandwidth than the GTX 960, which means that the memory performance of the Radeon R9 280X is massively better than the GTX 960.
The GeForce GTX 960 2GB has 1024 Shader Processing Units and the Radeon R9 280X has 2048. However, the actual shader performance of the GTX 960 is 1628 and the actual shader performance of the Radeon R9 280X is 1741. The Radeon R9 280X having 113 better shader performance and an altogether better performance when taking into account other relevant data means that the Radeon R9 280X delivers a massively smoother and more efficient experience when processing graphical data than the GTX 960.
The GeForce GTX 960 2GB requires 120 Watts to run and the Radeon R9 280X requires 250 Watts. We would recommend a PSU with at least 400 Watts for the GTX 960 and a PSU with at least 750 Watts for the Radeon R9 280X. The Radeon R9 280X requires 130 Watts more than the GTX 960 to run. The difference is significant enough that the Radeon R9 280X may have an adverse affect on your yearly electricity bills in comparison to the GTX 960.
