[the_duke]

I'm pretty sure they are aware of it.

I have the same issues on Linux. It's really fast, but often it hogs one core completely and the CPU does a lot of work, sending the fans in overdrive. Especially when videos are involved.

Let's hope things get ironed until a stable release in november

[nachtigall]

As said in sibling: Open a bug report at https://bugzilla.mozilla.org/

Mention Quantum Flow and "performance" in it. Make sure to attach a performance profile with https://perf-html.io/ using the linked add-on there.

I had many cases where the mozilla devs were glad about such bug reporst (especially if you are on Linux - I am too :) - which is not so often used and reported like Windows or Mac)

[spiderfarmer]

Done: https://bugzilla.mozilla.org/show_bug.cgi?id=1407536

[dao-]

We're aware that there seems to be a problem, but we can't reproduce it yet: https://bugzilla.mozilla.org/show_bug.cgi?id=1404042 Any additional data points, test cases etc. are appreciated.

[spiderfarmer]

I filed a new report here, with perf.html attached: https://bugzilla.mozilla.org/show_bug.cgi?id=1407536