This year the open-source NVIDIA Linux driver (Nouveau) continued to evolve with improvements for re-clocking, the start of OpenGL 4 support, and other new functionality. Here's a recap along with some performance benchmarks showing how the OpenGL performance evolved over the past 12 months.
Over 2015 the Nouveau NVC0 driver for Fermi and newer GPUs received OpenGL 4.1 support along with various other OpenGL 4 extensions. This reverse-engineered, community-based driver is basically on par right now with the RadeonSI Gallium3D driver for OpenGL 4 support and actually beat RadeonSI to exposing OpenGL 4.1. The Nouveau driver stack also made other progress this year when it comes to working on compute/OpenCL support, texture compression (including ETC2 and ASTC), video acceleration, and other features.
With the Linux 4.2 kernel there was the big DRM driver rework to restructure the code and offer improvements going forward. The Nouveau user-space recently landed the support for using the new kernel interfaces to enhance the driver's design, lower memory use, and faster GPU virtual memory.
One of the areas of most interest to Nouveau users -- and potential users -- has been on the re-clocking front. In 2015 were some re-clocking improvements, particularly for making Kepler re-clocking better and more stable.
With the in-development Linux 4.4 kernel, Kepler GTX 600/700 re-clocking is working for more cards but still not perfect even with out-of-tree, experimental patches. This is a big task at hand and unless NVIDIA begins contributing documentation or code, it will likely be several more kernel revisions before everything is ironed out.
On the downside, ending out 2015 there is still no support for open-source hardware acceleration for the GeForce GTX 900 "Maxwell" series. Nouveau developers find the latest-generation hardware to be very open-source unfriendly and are waiting on NVIDIA to released the needed signed firmware images. That will hopefully happen soon, albeit it's been over a year since the first GeForce GTX 900 series hardware launched. Hopefully all of this will get squared away in early 2016.
On the bright side, NVIDIA continues working on Nouveau code as it pertains to the Tegra SoCs with Kepler/Maxwell graphics processors. NVIDIA pushed out a lot of code this year for Tegra X1 support with its GM20B GPU. NVIDIA has also released some other documentation this year that also helps out the desktop crew. Interestingly, the Google Pixel C tablet uses the Nouveau kernel driver on Android.
Well, those were the prominent advances for this open-source NVIDIA Linux driver in 2015. On the following pages are benchmarks for a few GeForce graphics cards comparing the performance.