But on every machine I've put the new FF on, the
startup time for it ranges from 2-5 minutes
What? Is this a typo? Do you mean seconds?
I've never seen that on any machine and again, this is many dozens of computers over the years, including one company where FF was the standard browser for the company enterprise/intranet app so thousands of people were using it all day long.
and the initial load time for web pages is
achingly slow (sometimes up to a minute or so).
It's not a typo. It's also not a particular machine. It's all of my machines.
It's why I stopped using Firefox. It wasn't always like that -- pre-quantum, Firefox was reasonably performant. And post-quantum it was as well (although I never saw the performance gains others reported). I don't remember which release this started happening in, but it was a couple of years ago.
Just to forestall advice -- every time I've mentioned this, people have engaged with me to make sure it's not the usual issues (have I completely erased FF and installed it fresh, am I using extensions, etc.). And many think I'm lying.
But this is my actual experience with Firefox. I was willing to stick with using it on principle despite the fact that post-quantum firefox does a poor job if meeting my browser needs, but I couldn't. It's essentially unusable for me.
Does the issue persist on other networks? I wonder if it's a DNS/proxy/something issue.
I don't know the particulars, but Firefox does some talking over the network at startup. It checks for browser updates, blocklist updates, captive portal detection, etc. I am not certain which if any of these happen at startup, and AFAIK none of these are blocking (but I admittedly have only the vaguest knowledge here)
I've not tried with those machines on a different network. I assume it's related to networking in some way. My network is more complex than most. All of these machines are Linux (Debian). I haven't experienced this on Windows machines at work (although I also haven't noticed that Firefox had become any faster on them).
I wonder what happens if you launch FF with your wifi disabled and/or the cable unplugged?
On MacOS and Windows (I can try this on PopOS as well if you like) FF launches instantly with no complaints if the network is down. Which tells me that FF seems to properly handle situations where things are merely unreachable.
The fact that it's hanging for you implies to me that perhaps FF is getting some kind of malformed response from... something on your network. A firewall, a proxy, I don't know.
I've not tried with those machines on a different
network. I assume it's related to networking in some
way. My network is more complex than most.
I don't know if you're open to feedback on this or not, but it feels disingenuous to state "Firefox is unusably slow" without noting that it appears to be some specific interaction between Firefox and your network. If it is a network issue, it certainly sounds like it is something FF should handle more gracefully/informatively, but that is a different matter from "Firefox unusably slow."
> it feels disingenuous to state "Firefox is unusably slow" without noting that it appears to be some specific interaction between Firefox and your network.
I don't think it's disingenuous because it's only Firefox that has this issue. Every other browser is fine.
I think there's an edge-condition bug in Firefox that I'm triggering that causes this. I've spent quite a while trying to work this out before giving up entirely. However -- since it's really not at all hard to find people who have performance problems with Firefox generally, there is something going on with it. And it's something that (based on interactions with the dev team) Mozilla seems not willing to worry much about.
All that said, I try very hard to be fair to Mozilla and Firefox, in part because I've been a huge backer of Firefox since the very beginning, and still care.
I've never seen that on any machine and again, this is many dozens of computers over the years, including one company where FF was the standard browser for the company enterprise/intranet app so thousands of people were using it all day long.
This is absolute madness.