In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce 9400 GT 1GB are marginally better than the AMD Radeon HD 4290.

The Radeon HD 4290 was released over a year more recently than the 9400 GT, and so the Radeon HD 4290 is likely to have better driver support, meaning it will be more optimized for running the latest games when compared to the 9400 GT.

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 9400 GT has 896 MB more video memory than the Radeon HD 4290, so is likely to be much better at displaying game textures at higher resolutions. This is supported by the fact that the 9400 GT also has superior memory performance overall.

The 9400 GT has 12.8 GB/sec greater memory bandwidth than the Radeon HD 4290, which means that the memory performance of the 9400 GT is slightly better than the Radeon HD 4290.

The GeForce 9400 GT 1GB has 16 Shader Processing Units and the Radeon HD 4290 has 40. However, the actual shader performance of the 9400 GT is 9 and the actual shader performance of the Radeon HD 4290 is 18. The Radeon HD 4290 having 9 better shader performance is not particularly notable, as altogether the 9400 GT performs better when taking into account other relevant data.

The Radeon HD 4290 transistor size technology is 10 nm (nanometers) smaller than the 9400 GT. This means that the Radeon HD 4290 is expected to run very slightly cooler and achieve higher clock frequencies than the 9400 GT. While they exhibit similar graphical performance, the Radeon HD 4290 should consume less power than the 9400 GT.

The GeForce 9400 GT 1GB requires 50 Watts to run but there is no entry for the Radeon HD 4290. We would recommend a PSU with at least 300 Watts for the 9400 GT.