In the lead-up to releasing Phoronix Test Suite 4.4.1-Forsand, a wide variety of hardware is always benchmarked to ensure there are no last minute bugs or other snafus concerning the Phoronix Test Suite client itself, the Phoronix Device Interface (Phodevi) library for hardware/software detection, or any other problems. One of the combinations tested was the NVIDIA and Nouveau drivers from a Quadro NVS 140M laptop since it hasn't been tested in a while at Phoronix.
The Quadro NVS 140M was found within a Lenovo ThinkPad T61 notebook that had an Intel Core 2 Duo T9300 "Penryn" processor. The Quadro NVS 140M is derived from the "G86M" core that is about equivalent to a NVIDIA GeForce 8500GT. This laptop is approaching five years of age and when testing Nouveau at different times in the past the mileage has varied.
Nouveau has supported the Quadro NVS 140M for years with its GeForce 8 enablement, but the support has regressed from time to time. With Ubuntu 13.04 right now it's still on the Mesa 9.0 stable series with the Linux 3.8 kernel. Upon a fresh install of Ubuntu 13.04 as of this week, the Nouveau state was rather poor. There were different rendering issues with the Compiz-based desktop for this hardware on Nouveau:
Nouveau driver support is still like a game of Russian Roulette.
Nouveau also only saw 128MB of VRAM available where as the NVIDIA driver could access all 512MB. The NVIDIA binary blob on this hardware worked fine. The Nouveau driver by default was also running the hardware with a 275MHz core clock as set by the video BIOS, since the Nouveau DRM driver doesn't yet have "out of the box" or dynamic re-clocking for actually running the GPU at its rated speeds. The GPU should be running at 400MHz.
For the light OpenGL Linux games that were able to run on the Nouveau driver for the NVIDIA Quadro NVS 140M without causing havoc on the Ubuntu Linux laptop, the results were at least decent when compared to the NVIDIA binary driver and considering the clock-speed differences. But too bad this is half-decade old hardware still regressing with Nouveau.
More Nouveau vs. NVIDIA driver OpenGL Linux results can be found from this system within 1303144-FO-NOUVEAUNV19. For desktop NVIDIA GeForce graphics cards, a new driver comparison using the very latest driver code is coming soon on Phoronix, but until then there is the Five-Way NVIDIA GeForce Comparison On Nouveau from January.