But GpuTest is working now, yay!
If I use the (recommended) drivers, nvidia-319, it fails. But as you said, most of them work well with Nouveau driver. TessMark's, GiMark and PixMark Julia FP64 aren't working, let me know if you want the log file for them.
It's normal, all these benchmark require OpenGL 3.3 or OpenGL 4.0 support and Nouveau driver is limited to OpenGL 2.1 or maybe 3.0 I can't remember.
I'm glad it works, and also saddened to get the results I feared...
I have a GTX 460 768mb, which is not bad I believe, and get 3-4 FPS on the FurMark test, 1024x640 windowed mode. Same with PixMark Volplosion: 3 FPS.
Same reason: Nouveau driver: Nouveau driver is slow and does not show the performance of your GTX 460. When you will manage to install real NV driver, you will see the difference. So don't panic, your GTX 460 is not dead