Arcturus No Longer Experimental - AMD Instinct MI100 Linux Support Is Ready

Being sent in as a "fix" this week to the Linux 5.10 kernel is removing the experimental flag for the Arcturus GPU, days after AMD announced the MI100 accelerator at SC20.

Going back to the summer of 2019 there have been Linux graphics driver patches for "Arcturus" as an evolution of GFX9/Vega but with not a lot being known about it. Much work was poured into this open-source driver code for Arcturus and the Linux support all squared away over the past year. This week it finally entered the limelight in the form of the AMD Instinct MI100 accelerator.

Now that this HPC accelerator is shipping beginning this month, the AMD Linux developers are promoting the Arcturus support from behind its "experimental" flag. On existing kernel releases to boot the AMDGPU DRM driver with Arcturus enabled it requires setting the amdgpu.exp_hw_support=1 module parameter, but by removing the experimental flag it's considered stable and no longer requires that workaround.

One may ask why it took until launch week to remove that experimental flag, but it likely came down to waiting until they were able to test with the finalized cards to ensure no vBIOS changes or other last minute changes led to driver issues as we have sometimes seen in the past. In any case, with Linux 5.10 (and possibly backported?) the Arcturus support is no longer being treated as experimental.

The timing of this ultimately isn't that important either considering the workstation/HPC focus. There most customers are on enterprise Linux distributions running their (dated) enterprise kernels and almost exclusively relying upon the packaged driver components from AMD that go through all of their QA/certification processes. Those customers don't buy pricey hardware just to be habitually running Linux Git and other bleeding-edge open-source packages in order to support their critical work. The packaged driver will surely be in good shape for the MI100 and ready to go.

Besides dropping the experimental flag on Arcturus, this week's AMDGPU fixes also include a page-flipping fix for Navi 1x hardware when using 5 or 6 displays.

Linux 5.10 stable should be out by mid-December.