In terms of overall gaming performance, the graphical capabilities of the AMD Radeon HD 4290 are massively better than the Nvidia GeForce 4 MX 440.

The Radeon HD 4290 was released over three years more recently than the 4 MX, and so the Radeon HD 4290 is likely to have far better driver support, meaning it will be much more optimized and ultimately superior to the 4 MX when running the latest games.

Both GPUs exhibit very poor performance, so rather than upgrading from one to the other you should consider looking at more powerful GPUs. Neither of these will be able to run the latest games in any playable way.

The Radeon HD 4290 and the GeForce 4 MX 440 have the same amount of video memory, but are likely to provide slightly different experiences when displaying game textures at high resolutions.

The 4 MX has 3.2 GB/sec greater memory bandwidth than the Radeon HD 4290, which means that the memory performance of the 4 MX is marginally better than the Radeon HD 4290.

The Radeon HD 4290 has 40 Shader Processing Units and the GeForce 4 MX 440 has 2. However, the actual shader performance of the Radeon HD 4290 is 18 and the actual shader performance of the 4 MX is 1. The Radeon HD 4290 having 17 better shader performance and an altogether better performance when taking into account other relevant data means that the Radeon HD 4290 delivers a marginally smoother and more efficient experience when processing graphical data than the 4 MX.