In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce GTX 680M SLI are massively better than the AMD Radeon R9 M365X 4GB.

The GTX 680M has a 95 MHz higher core clock speed and 184 more Texture Mapping Units than the R9 M365X. This results in the GTX 680M providing 136.3 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 680M has a 95 MHz higher core clock speed and 48 more Render Output Units than the R9 M365X. This results in the GTX 680M providing 36.1 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 three years more recently than the GTX 680M, and so the R9 M365X is likely to have far better driver support, meaning it will be much more optimized and ultimately superior to the GTX 680M when running the latest games.

The Radeon R9 M365X 4GB and the GeForce GTX 680M 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 680M has 166.4 GB/sec greater memory bandwidth than the R9 M365X, which means that the memory performance of the GTX 680M is massively better than the R9 M365X.

The Radeon R9 M365X 4GB has 640 Shader Processing Units and the GeForce GTX 680M SLI has 2688. However, the actual shader performance of the R9 M365X is 340 and the actual shader performance of the GTX 680M is 1935. The GTX 680M having 1595 better shader performance and an altogether better performance when taking into account other relevant data means that the GTX 680M delivers a massively 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 GTX 680M SLI requires 200 Watts. The GTX 680M requires 150 Watts more than the R9 M365X to run. The difference is significant enough that the GTX 680M may have an adverse affect on your yearly electricity bills in comparison to the R9 M365X.