I haven't run any Nouveau driver benchmarks recently for looking at the open-source NVIDIA Linux performance since there hasn't been too much progress, particularly when it comes to re-clocking of the desktop GPUs for delivering better performance. However, with all the testing I've been doing on the Radeon side with Linux 4.8 and Mesa 12.1-dev Git, I decided to do a comparison with a few NVIDIA GeForce GPUs under this latest open-source driver stack.
On Linux 4.8, Kepler class GPUs (GeForce 600/700 series) remain best off for their reclocking potential in being able to deliver better performance. With the cards I tested, I was able to manually re-clock each of them to their highest performance state (0f) but there isn't yet any dynamic reclocking support nor are there the Nouveau DRM boost patches mainlined yet for being able to reach their boost frequencies.
The GeForce 900 "Maxwell" graphics cards can run with accelerated graphics when using a recent kernel and the latest signed firmware blobs. However, there is no re-clocking support. Nouveau developers have been trying to work on Maxwell (GTX 900) re-clocking but their hands are tied without having more firmware support from NVIDIA. Besides the headaches of reclocking itself, they aren't even able to alter the fan-speed themselves due to firmware restrictions imposed by NVIDIA beginning with Maxwell until having access to the PMU firmware. With the GeForce GTX 1000 (Pascal) cards there is no open-source accelerated support at all until NVIDIA releases the signed firmware blobs.
So for this comparison it was mostly focused on Kepler cards with the GTX 650, GTX 680, GTX 760, and GTX 780 Ti. All of those cards re-clocked to 0f and were tested that way. For some Maxwell coverage was a GTX 980 Ti. I compared these Nouveau numbers to various Radeon GPUs.
Linux 4.8 Git with the Mesa 12.1-dev Git stack was used for testing all of the graphics cards in this comparison atop Ubuntu 16.04 LTS x86_64. With some of the OpenGL games, there were issues with Nouveau. Metro Last Light Redux was hanging at the loading screen, BioShock Infinite was running into hangs and corruption on a few of the cards, and Dota 2 was also struggling in a similar manner on some of the hardware.
On the pages ahead are these basic Nouveau results for those curious about the current state of this open-source NVIDIA Linux driver.