In terms of overall gaming performance, the graphical capabilities of the AMD Radeon R9 390X XFX Double Dissipation Black 8GB Edition are noticeably better than the Nvidia GeForce GTX 960 Ti 4GB.

The R9 390X has a 40 MHz higher core clock speed and 80 more Texture Mapping Units than the GTX 960 Ti. This results in the R9 390X providing 91 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 R9 390X has a 40 MHz higher core clock speed than the GTX 960 Ti and the same number of Render Output Units. This results in the R9 390X providing 2.6 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 Ti was released less than a year after the R9 390X, 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 R9 390X has 4096 MB more video memory than the GTX 960 Ti, so is likely to be much better at displaying game textures at higher resolutions. This is supported by the fact that the R9 390X also has superior memory performance overall.

The R9 390X has 159.6 GB/sec greater memory bandwidth than the GTX 960 Ti, which means that the memory performance of the R9 390X is massively better than the GTX 960 Ti.

The Radeon R9 390X XFX Double Dissipation Black 8GB Edition has 2816 Shader Processing Units and the GeForce GTX 960 Ti 4GB has 1536. However, the actual shader performance of the R9 390X is 2609 and the actual shader performance of the GTX 960 Ti is 1809. The R9 390X having 800 better shader performance and an altogether better performance when taking into account other relevant data means that the R9 390X delivers a massively smoother and more efficient experience when processing graphical data than the GTX 960 Ti.

The Radeon R9 390X XFX Double Dissipation Black 8GB Edition requires 300 Watts to run and the GeForce GTX 960 Ti 4GB requires 140 Watts. We would recommend a PSU with at least 750 Watts for the R9 390X and a PSU with at least 450 Watts for the GTX 960 Ti. The R9 390X requires 160 Watts more than the GTX 960 Ti to run. The difference is significant enough that the R9 390X may have an adverse affect on your yearly electricity bills in comparison to the GTX 960 Ti.