(In reply to Ioannis Panagiotopoulos from comment #82)
> the environment was still slow, despite the Xorg.log
> stating that acceleration was on.

Yeah, that was a "low" profile, so it was expected to be slow��� You can do that
to get a "high" profile:

echo 'high' > '/sys/class/drm/card0/device/power_dpm_force_performance_level'
echo 'performance' > '/sys/class/drm/card0/device/power_dpm_state'

But by the way:

> The successful starts did not last very
> long however, as they crashed after 1-2 minutes.

If you still get a hang using a profile different than "auto" it looks like you
are facing an issue I never got myself��� It means the bug is wider than
expected, it's not a good news. I can't help more at this point, I hope someone
else will have an answer.