After a restart the gdm and the gnome desktop suddenly became very laggy. I noticed a lot of cpu usage and checked the about page in gnome setting, which showed that gnome was using software rendering even though it recognized the gpus in the system.
I suspect this is also has happened on some of my other systems.
How can I reenable hardware rendering, and why might it suddenly change to software rendering? There was no software update or user config change applied before the restart where the rendering changed.
The current system where I have narrowed it down to software rendering is running on the latest fedora release as of this writing. An other system where I also have noticed this slowdown, but I dont have access to at the moment, as it is a work machine, is running an hp-branded version of an ubuntu lts.
Whatever the issue is, you will have to ask your distribution. GNOME doesn’t do anything special, in order to have switched to software rendering something probably went wrong with some update in another component and now there is no viable Vulkan or GL backend available.