In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce 8400 GS are massively better than the Nvidia GeForce 4 MX 440.

The GeForce 8400 GS was released over three years more recently than the 4 MX, and so the GeForce 8400 GS 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 GeForce 8400 GS has 128 MB more video memory than the 4 MX, so is likely to be slightly better at displaying game textures at higher resolutions. This is supported by the fact that the GeForce 8400 GS also has superior memory performance overall.

The GeForce 8400 GS has 3.2 GB/sec greater memory bandwidth than the 4 MX, which means that the memory performance of the GeForce 8400 GS is marginally better than the 4 MX.

The GeForce 8400 GS has 16 Shader Processing Units and the GeForce 4 MX 440 has 2. However, the actual shader performance of the GeForce 8400 GS is 18 and the actual shader performance of the 4 MX is 1. The GeForce 8400 GS having 17 better shader performance and an altogether better performance when taking into account other relevant data means that the GeForce 8400 GS delivers a marginally smoother and more efficient experience when processing graphical data than the 4 MX.

The GeForce 8400 GS requires 18 Watts to run but there is no entry for the GeForce 4 MX 440. We would recommend a PSU with at least 300 Watts for the GeForce 8400 GS.