Open-Source NVIDIA Driver Works On Some GeForce 700 GPUs, Fails On Others

With being in the process of checking out several new NVIDIA GeForce 700 GPUs on Linux, now that I have out of the way the GeForce GTX 760 / 770 / 780 Ti / TITAN Linux benchmarks and Windows vs. Linux NVIDIA benchmarks, I decided to see how these four "Kepler" graphics cards are working with Nouveau, the open-source NVIDIA graphics driver that's written through clean-room reverse-engineering. Up until recently Nouveau has just been an open-source community project, except now NVIDIA is beginning to support Nouveau and open-source, so let's see how it runs on this latest high-end graphics hardware.

The graphics cards being attempted to run with the latest open-source Nouveau driver include the GeForce GTX 760, GTX 770, GTX 780 Ti, and GTX TITAN. All testing was done with the latest Nouveau code that included the Linux 3.13 Git kernel as of 26 November, Mesa 10.1-devel Git from the Oibaf Ubuntu PPA, and xf86-video-nouveau.

First up, when testing the GeForce GTX 780 Ti graphics card, the Ubuntu 13.10 operating system with the manually updated graphics driver components had loaded the Nouveau DRM driver but it was reported as an "unknown Kepler chipset" and soon after words was an error of "failed to create 0x80000080, -22" and then ultimately "probe of 0000:01:00.0 failed with error -22." Thus, with the GeForce GTX 780 Ti we were left without any form of hardware acceleration. That was also with the Linux 3.12 mainline kernel as when booting up the Linux 3.12 Git kernel with this graphics card installed it failed to mode-set.

When booting up the system with the GeForce GTX TITAN installed, the Nouveau driver error came down to "Error creating GPU channel: -19" and "Error initialising acceleration. Falling back to NoAccel." For this $1000 GPU, the Nouveau driver doesn't yet work for it and goes without hardware acceleration but could at least mode-set for the Linux 3.13 kernel.

When it came to testing the lower-end NVIDIA GeForce GTX 760 and GTX 770 graphics cards, they did work with Nouveau! To some amazement, hardware acceleration was working atop the NVE4 Gallium3D driver in Mesa 10.1-devel and there were no issues with the Linux 3.13 kernel.

The major issue though affecting NVIDIA "Fermi" (GeForce 400/500) and "Kepler" (GeForce 600/700) graphics processors though is the lack of proper re-clocking support within this driver. The newer NVIDIA GPUs are basically left to run at their core/shader/memory clock speeds that were programmed by the video BIOS at boot time. Generally, for higher-end GPUs these frequencies are very low and until the Nouveau driver can bump itself to higher performance stated, the performance suffers greatly.

Let's see what the Nouveau vs. NVIDIA binary driver performance is for these two working GeForce 700 series graphics cards.