Comment # 1 on bug 104602 from Jason Playne

I am seeing the same with my vega64 on KDE Neon with the oibaf ppa.

packages are marked as 17.4~git1801200730.436ed6~oibaf~x

kernel: 4.15.0-041500rc5-generic

You can easily reproduce this by running the graphics benchmark.

I tried to capture an API trace but the game slowed down so much that the
benchmark did not get far enough along to show it :( 

(it is entirely possible that I am holding it wrong too)