In terms of overall gaming performance, the graphical capabilities of the AMD Radeon R9 M365X 4GB are marginally better than the Nvidia GeForce GT 750M Mac Edition.

The GT 750M has a 301 MHz higher core clock speed but 8 fewer Texture Mapping Units than the R9 M365X. The lower TMU count doesn't matter, though, as altogether the GT 750M manages to provide 4.6 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 GT 750M has a 301 MHz higher core clock speed than the R9 M365X and the same number of Render Output Units. This results in the GT 750M providing 4.8 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 M365X was released over a year more recently than the GT 750M, and so the R9 M365X is likely to have better driver support, meaning it will be more optimized for running the latest games when compared to the GT 750M.

The R9 M365X has 2048 MB more video memory than the GT 750M, so is likely to be much better at displaying game textures at higher resolutions. However, overall, the GT 750M has superior memory performance.

The GT 750M has 16.2 GB/sec greater memory bandwidth than the R9 M365X, which means that the memory performance of the GT 750M is slightly better than the R9 M365X.

The Radeon R9 M365X 4GB has 640 Shader Processing Units and the GeForce GT 750M Mac Edition has 384. However, the actual shader performance of the R9 M365X is 340 and the actual shader performance of the GT 750M is 356. The GT 750M having 16 better shader performance and an altogether better performance when taking into account other relevant data means that the GT 750M delivers a slightly smoother and more efficient experience when processing graphical data than the R9 M365X.

The Radeon R9 M365X 4GB requires 50 Watts to run and the GeForce GT 750M Mac Edition requires 50 Watts. The two GPUs require the same amount of wattage to run. As such, there is no need to worry about which will more significantly affect your yearly electricity bills.