In terms of overall gaming performance, the graphical capabilities of the Nvidia Quadro K4000M are noticeably better than the AMD Radeon HD 8850M.

The Radeon HD 8850M has a 24 MHz higher core clock speed than the Quadro K4000M, but the Quadro K4000M has 40 more Texture Mapping Units than the Radeon HD 8850M. As a result, the Quadro K4000M exhibits a 23.1 GTexel/s better Texture Fill Rate than the Radeon HD 8850M. 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 8850M has a 24 MHz higher core clock speed than the Quadro K4000M, but the Quadro K4000M has 16 more Render Output Units than the Radeon HD 8850M. As a result, the Quadro K4000M exhibits a 9.2 GPixel/s better Pixel Fill Rate than the Radeon HD 8850M. However, both GPUs support DirectX 9 or above, and pixeling performance is only really relevant when comparing older cards.

The Radeon HD 8850M was released less than a year after the Quadro K4000M, and so they are likely to have similar driver support for optimizing performance when running the latest games.

The Quadro K4000M has 2048 MB more video memory than the Radeon HD 8850M, so is likely to be much better at displaying game textures at higher resolutions. This is supported by the fact that the Quadro K4000M also has superior memory performance overall.

The Quadro K4000M has 57.6 GB/sec greater memory bandwidth than the Radeon HD 8850M, which means that the memory performance of the Quadro K4000M is much better than the Radeon HD 8850M.

The Radeon HD 8850M has 640 Shader Processing Units and the Quadro K4000M has 960. However, the actual shader performance of the Radeon HD 8850M is 496 and the actual shader performance of the Quadro K4000M is 577. The Quadro K4000M having 81 better shader performance and an altogether better performance when taking into account other relevant data means that the Quadro K4000M delivers a significantly smoother and more efficient experience when processing graphical data than the Radeon HD 8850M.

The Radeon HD 8850M requires 45 Watts to run and the Quadro K4000M requires 100 Watts. The Quadro K4000M requires 55 Watts more than the Radeon HD 8850M to run. The difference is significant enough that the Quadro K4000M may have an adverse affect on your yearly electricity bills in comparison to the Radeon HD 8850M.