Why have recent Nightlies become so sluggish?

[asampal]

I've noticed that recently (maybe for the last week or two?) Nightlies (Windows 10 64 bit) have become quite sluggish. I keep lots and lots of tabs around (though not many loaded) and these days I always see the loading animation go on for a while whereas before things loaded pretty quickly. Has anything major changed? Will decent performance return? The way it feels now, I can't see myself sticking with Firefox for too much longer. In the performance thread, I saw that there was talk of a recent JavaScript performance regression - is that what I'm seeing?

[malliz]

Did you try any trouble shooting?

[Virtual_ManPL]

If you're using e10s, yes, it's less performant compared to non e10s.
So disable e10s, if you're caring about speed, not snappy and responsibility.

Also don't forget that stable builds are better optimized.
Nightly has enabled some extra debugging code like memory poisoning etc., which makes Nightly slower in tests etc.

[GHM113]

NoScript is the source of the problem. Thread on the official forum:
https://forums.informaction.com/viewtop ... 10&t=21828
More info here:
https://bugzilla.mozilla.org/show_bug.c ... 058542#c70
According to this bug, Mozilla might patch Firefox so that it performs well with NoScript installed:
https://bugzilla.mozilla.org/show_bug.c ... 264896#c10

[asampal]

Did you try any trouble shooting?

Haven't yet - thought I'd ask first since performance is something that, for me, has changed noticeably just recently and I haven't done anything wrt adding new extensions, changing my workflow, etc. I assumed others might have noticed too.

[asampal]

If you're using e10s, yes, it's less performant compared to non e10s.
So disable e10s, if you're caring about speed, not snappy and responsibility.

Also don't forget that stable builds are better optimized.
Nightly has enabled some extra debugging code like memory poisoning etc., which makes Nightly slower in tests etc.

I am not using e10s (though I think at some point I had enabled it - it now is disabled, and I'm not sure what caused that). Of course, I'm not comparing the Nightlies to stable builds, but just relatively - the most recent ones seem, for me, to not be very responsive compared to how Nightlies used to run a week or so ago.

[asampal]

NoScript is the source of the problem.

Unfortunately this can't be it for me since I don't use it.

[y-koron]

Current nightly has a problem about GC performance with e10s (https://bugzilla.mozilla.org/show_bug.cgi?id=1264896) and some heavy add-ons like NoScript triggers browser unresponsive state easily.