I'll answer my own question. I bought a new video card and ran the gpu banchmark on both cards. NVIDIA drivers 169.04 beta on both cards under Windows XP 32 bits. Resolution : 1280x960, 32 bits. No AA and all settings on medium. EVGA 7900 GT KO, core:500MHZ, memory:750 MHZ. min FPS : 6.90 max FPS : 35.42 average FPS : 22.70 Gigabyte 8600 GT, core:600MHz, memory:720MHz. min FPS : 14.58 max FPS : 37.96 average FPS : 25.25 The 7900 GT is a Dx9 card and the 8600 GT a DX10 card. I did not force the use of DX9 or DX10 on any of the cards. I was afraid that the 8600 GT would be a downgrade from the 7900 GT. It does not seem to be the case. I bought the passive version of the card so there's no fan on it (less noise). In the end, I'm pleased with my purchase even if it's not a big improvement for gaming. It should play HD movies with a lower cpu usage and it's less noisy.