https://bugs.freedesktop.org/show_bug.cgi?id=92059
--- Comment #16 from Kai kai@dev.carbon-project.org --- (In reply to Kai from comment #15)
On the upside: the FPS graph shown with radeonsi looks way more stable than the one I've seen with fglrx (like saw teeth), though that might just be due to the shaders not executed so far. With the stack detailed below, I also managed to get to > 60 FPS in some parts of the benchmark, while I barely saw 40 with the stack from comment #0. On the other hand, I'm still seeing drops to single digit frame rates (just above 3 FPS).
Sorry about the reported FPS increase to 60+: the game settings had dropped (I have no idea why, I didn't change them). It's still better than before with the current stack, but not so much, that I would mention it.