Comment 50 for bug 1959747

(In reply to Fabian Rodriguez:MagicFab from comment #13)
> I see at least two reports confirming this in Mozilla Thunderbird support, including Windows, Mac and GNU/Linux - and I have the same problem (TB 91.1.2 on Windows 10).
>
> This makes Thunderbird slow to the point it can't be used normally.
>
> A possible workaround was mentioned here :
> https://support.mozilla.org/en-US/questions/1347196#answer-1435915
>
> > If I go to preferences --> config editor and search for the entries:
> >
> > gfx.webrender.all
> > gfx.webrender.force-disabled
> >
> > Switch the first one to false (it was already switched to false) and the second one to true (I switched this one manually)
> > everything works smooths and no cpu usage jumps happen.
>
> I suggest raising importance/severity. People upgrading seldom backup their Thunderbird profile and when this happens, all the usual "Thunderbird is slow" are being tried without a solution, bringing a user closer to stop using Thunderbird and go to other options.
>
> A few references to people reporting this problem :
>
> * https://support.mozilla.org/en-US/questions/1347196
> * https://support.mozilla.org/en-US/questions/1351874

The mentioned parameter (gfx...force-disabled) is gone from configuration in 102 . Reinstating the parm helps some but doesn't fix the 100% CPU utilization. (5.15.0-52-generic #58~20.04.1-Ubuntu SMP on Intel Core i7-2760QM)