Benchmarking The Intel Ivy Bridge Gallium3D Driver
While Intel only supports their classic Mesa DRI driver when it comes to their open-source 3D driver on Linux, developed independently is also a Gallium3D driver for Sandy Bridge and Ivy Bridge generations of Intel graphics processors. In this article are benchmarks of the new Intel (i965) Gallium3D driver with Ivy Bridge HD 4000 hardware.
There was an unofficial i965 Gallium3D driver in the past, but it was ultimately removed when the code fell into bit rot and really didn't have any users. There's also the i915 Gallium3D driver that is still maintained independently for supporting old i915 and i945 graphics hardware, but Intel Open-Source Technology Center developers only officially support their classic Mesa drivers.
Back in December was when Chia-I Wu of LunarG started a new Intel Gallium3D driver to support the last two generations of Intel graphics hardware: Sandy Bridge and Ivy Bridge. This basic Gallium3D driver was developed independently based upon public Intel hardware documentation and the existing i965 Mesa driver. While there was some confusion over its state, it turns out the Gallium3D driver is still being maintained out-of-tree. Chia-I Wu ended up moving his i965g development to a different Git repository branch: i965g-next.
The most recent developments to this modern Intel Gallium3D driver happened just hours ago and there's been ongoing work on a regular basis within this "i965g-next" repository. Chia-I hasn't publicly pushed for mainlining this driver as an alternative within Mesa yet and the ultimate game plan for this driver isn't clear. Anyhow, I figured it would be interesting for some tests to see how the two i965 Intel drivers compare.
With the latest i965g-next code as of 15 April, the classic i965 Mesa and i965 Gallium3D drivers were compared from the same Git revision and same build options. Switching out the i965 driver was the only change between testing on this Intel Core i7 3517UE "Ivy Bridge" system with HD 4000 graphics and running Ubuntu 13.04.
For being a driver that's a few months old, the OpenGL support was fairly good. The only major visual bug hit during testing was when running Nexuiz at lower resolutions than the native resolution yielded some problems:
That was the only rendering problem to note. Now let's look at the performance results.