In terms of overall gaming performance, the graphical capabilities of the AMD Radeon HD 8790M are significantly better than the Nvidia GeForce 920M 2GB.

The Radeon HD 8790M has a 275 MHz higher core clock speed but 8 fewer Texture Mapping Units than the GeForce 920M 2GB. The lower TMU count doesn't matter, though, as altogether the Radeon HD 8790M manages to provide 2 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 Radeon HD 8790M has a 275 MHz higher core clock speed than the GeForce 920M 2GB and the same number of Render Output Units. This results in the Radeon HD 8790M providing 2.2 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 GeForce 920M 2GB was released over a year more recently than the Radeon HD 8790M, and so the GeForce 920M 2GB is likely to have better driver support, meaning it will be more optimized for running the latest games when compared to the Radeon HD 8790M.

The GeForce 920M 2GB and the Radeon HD 8790M have the same amount of video memory, but are likely to provide slightly different experiences when displaying game textures at high resolutions.

The Radeon HD 8790M has 49.6 GB/sec greater memory bandwidth than the GeForce 920M 2GB, which means that the memory performance of the Radeon HD 8790M is noticeably better than the GeForce 920M 2GB.

Both the GeForce 920M 2GB and the Radeon HD 8790M have 384 Shader Processing Units. While the two GPUs have the same number of SPUs, the actual performance delivered by the GeForce 920M 2GB is 366 and by the Radeon HD 8790M is 294. Knowing that the shader performance of the GeForce 920M 2GB is superior, it is not necessary to examine the GPUs' respective Texture and Pixel Fill Rates.

The GeForce 920M 2GB requires 25 Watts to run and the Radeon HD 8790M requires 35 Watts. The Radeon HD 8790M requires 10 Watts more than the GeForce 920M 2GB to run. The difference is not significant enough for the Radeon HD 8790M to have a noticeably larger impact on your yearly electricity bills than the GeForce 920M 2GB.