[blauditore]

Thanks for the hint, though I'm facing the issue on Ubuntu only (on Windows, everything seems fine). I think I've made the same investigation before, but to no avail.

HW_COMPOSITING says "unavailable by default: Hardware compositing is disabled", and OPENGL_COMPOSITING something similar. This corresponds with my experience of jumpy scrolling and Youtube making the the fans go berserk.

But apparently, WebGL isn't affected by this and performs okay.

[DiThi]

If you use KDE, try disabling compositing with Shift+Alt+F12.

[blauditore]

I'm on Unity (and probably Gnome Shell sooner or later).