[capitainenemo]

What version of Firefox? Graphics acceleration may be enabled in X11 but not in Firefox. Check the about:support page for status of that in the Graphics section. Last year I believe they enabled it by default in Linux due to improved driver stability, but there is still a blacklist. Chrome and Firefox both have blacklists, each with different card strings in it.

Over here it is: Compositing WebRender (I have layers.acceleration.force-enabled;true and gfx.webrender.all;true)

There's a far less common problem where you are running firefox in XRDP or ssh -YC and it is being sluggish - for that you have to force-enable xrender https://bugzilla.mozilla.org/show_bug.cgi?id=1263222 )

[dragosmocrii]

All the flags to force using acceleration are enabled, but the section with the Graphics driver shows that no driver was found. I do have the latest Nvidia Drivers installed, and my graphic card is a GeForce GTX 1660 Ti Mobile.

* Running Firefox 93.0

*Update: I've rebooted my system, and it shows that my Graphic Card is now in use. Not sure which flag I enabled helped, but pages are buttery smooth as with Chrome. Many thanks!

[capitainenemo]

If you'd flipped any graphics flags in about:config, system reboot was probably overkill (unless you'd updated system drivers too).

Most likely just needed to restart Firefox. But glad you got it working.

And yeah, both Chrome and Firefox on Linux can be rather finicky with graphics cards due to high levels of unreliability in the past. Although the situation has improved over time.