Firefox 86.0 more memory hungry than previous versions?

I have the bad habit of continuously having several Firefox windows with lots of tabs open (a few hundred or so). However, this hasn’t been an issue performance-wise for years. After the last update, I repeatedly get warnings about memory being low and, in fact, its memory footprint is quite heavy (at present 5.5 GB).

Whilst it might be a good idea to change my habits, I mainly wonder whether other people have had a similar experience, i.e. FF managing its data differently now or sudden warnings about high memory usage.

When I get these warnings I modify configuration as this:

browser.cache.disk.smart_size.enabled       False 
restart Firefox
browser.cache.disk.capacity                 1048576 is default
I put 2097152 doubling it.
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I’ll give it a try. Thanks!

Same here.

Life is short. I would recommend to improve more important things than such a minuscule problem. :wink:

It always depends on the type of tabs you have opened. If you have a lot of heavy tabs, where people freak out with JavaScript and then even a hundred YouTube tabs, then yes, this is normal. However, if you have only simpler sites opened, even if it were much more, it can be more bearable, from a resource perspective.

I am using FireFox since more than 15 years, with tiny breaks in-between.

My experience tells me, that there are sometimes bugs in FireFox, changing the behaviour, sometimes just the way you experience one. I still remember the time when an update delivered with a memory leak, leading to my browser eating up 40+ GB RAM.

Where do these warnings originate from?

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FF itself. A yellow banner just under the address bar.

It doesn’t seem to be a memory leak.

Great, with my 48GB, I have never seen such warning ever. :laughing:

However, that means your computer has not enough memory for FireFox to work properly.

As life is short, I would recommend you to invest the 100 CHF for increasing the RAM, rather than changing your lifestyle.
Obviously, I am biased, because that is exactly the way I personally decided to take. :wink:

Otherwise, if you do not want to change your lifestyle, but also don’t want to spend the 100 CHF right at this moment, then you can use workarounds, like e.g. the one @R_G proposed, where you transform RAM usage to disk usage.
However, the fitness of this solution also depends on your storage solution.

My main storage solution for the OS is an M.2 Samsung 9xx SSD (super fast, high end), so I wouldn’t want to clutter it with FireFox caches. I would recommend this behaviour to you, as well, if you have a similarly typed storage solution built into your computer.

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To make it clear: On my desktop (32 GB RAM), this doesn’t happen. On my laptop (8 GB) it does, but what stroke me as odd was that I didn’t see this warning until a couple of days ago. Therefore, my question whether it had anything to do with the recent update.

I didn’t notice any change in behaviour, since the most recent update.

Though, my point was, that if it only takes this 1GB (or how much it is now) more to make your FireFox put out a warning, then you are low on RAM, anyway, even without the warning. If you are not able to upgrade RAM in your Laptop, then you have to either accept your fate or use one of the alternative solutions proposed above.

All that said, ever thought of the case, that the only thing that changed with the update is that the banner was added and perhaps you were already always “low” on RAM, even before the banner existed? :wink:

From what I see in the release notes, the banner doesn’t seem to be new.

Well, perhaps you were always just one step away from the banner being shown and now this line has been crossed.

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That’s called a “tipping point”. Anyway: Correlation is not causality and I was just curious.
However, thanks for linking the release notes. Didn’t find anything regarding memory management, tab unloading etc. So, it’s probably just coincidence.

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Indeed, but I think it’d be tough to find the actual reason. Theoretically, something outside of FireFox might’ve increased RAM usage, leaving FireFox with a reduced amount of available RAM at disposal.

Interesting discussion, well-reasoned. When you both get as old as I am, you will find the problem goes away because you won’t be able to keep track of more than five or six tabs at any one time. Senior moments come at you thick and fast. There’s wisdom in the KISS principle.


In the end, following some advice in another forum, I replaced the Zen-kernel with the standard kernel, and memory usage went down from 5.5 GB to 3.5. Problem solved, for now. I guess.

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