User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0
Steps to reproduce:
Using Firefox 93.
With Firefox 93 Mozilla is throwing away OpenGL compositing (rendering), only Webrender stays.
User will need compatible GPU for Webrender, otherwise FF will use software Webrender.
Even with fully compatible GPU on systems with slow CPU Webrender works slower than OpenGL compositing (~ 20% slower).
Here for slow CPU I mean this: using FF loads CPU to 100% continuously.
I cannot find exact data about Webrender system requirements. It worked on AMD Terascale 2 with OpenGL 3.3 support. Maybe it'll work with all AMD/ATI Terascale chips (Radeon HD 2000 series and newer), but not previous ones.
Working OpenGL compositing option, as usual.
Please provide info about Webrender system requirements.