When running VDrift, the 9500GT, 9800GT, and GT 220 were all significantly faster than the NVIDIA binary driver (the 8500GT was unstable in this test too). However, even the Linux 2.6.38 kernel Nouveau DRM was faster than the binary driver. With VDrift, there is a strange phenomenon where the open-source Radeon and Nouveau drivers perform better than the proprietary drivers.
Lightsmark, the most demanding OpenGL test used, also saw significant performance boosts for the Nouveau driver when upgrading to the pre-RC1 Linux 2.6.39 kernel. The NVIDIA driver though was multiple times faster than the Nouveau 2.6.39 DRM on all of the tested graphics cards.