[boyaka]

Anecdote: Firefox (124) has become unusable for me on Arch Linux. Highly resource intensive applications (particularly including video streaming, even worse with camera / webrtc) consume way more CPU resources to the point of my laptop lagging out.

I don't remember the exact versions, but I upgraded to 124 earlier this month. Brave works great for video streaming, but breaks applications I use. Firefox development (125) also breaks some applications I use, and has the same performance issues as regular firefox.

The fan on my laptop has been broken for most of this year (replaced due to first fan making noise, but havent had time to figure out why the replacement stopped working). I have been running with all high performance CPU features disabled in the BIOS for years with the purpose of not using the fan anyways, and it has been working great with 1 or 2 intensive applications max running in firefox (and as much other low intensity stuff that basically doesn't consume much resource such as another browser - chromium, vscode, my development environment including a vm).

I don't currently really have any conclusive idea about what's going on. I will have to start using my desktop, fixing issues with my laptop, and do some more testing out of my workloads. Overall I'm just getting the feeling that something is horribly wrong with Firefox.

[ivanjermakov]

If you encounter it again, consider creating a performance snapshot with profiler and submitting a bug to the FF tracker: https://bugzilla.mozilla.org

[free_bip]

Sounds like a hardware decoding issue to me