On Friday, 28 May 2021 at 00:04:22 UTC+1, Paul wrote:

Remove the 64-bit version of Firefox you are running
and use the 32-bit one instead.

This bounds memory usage to 2GB on the 64-bit OS.
That's because the 32-bit address space is split
into 2GB user:2GB kernel space, and it cannot
grab more than 2GB on you.

This is called "keeping greedy Firefox in a cage".

Recommended min memory on the laptop would be 3GB
(which is by chance, what mine has, a 1GB stick,
a 2GB stick). The idea is, if the machine had that
much memory, Firefox might auger in, but leaving
your OS still running. If the machine has the
recommended minimum (1GB RAM installed), then
it's not going to work well running either version.

I don't find Firefox an issue - but I do have plenty of RAM. 16GB on the machine I'm now using. Firefox uses less than 2 GB despite having about forty tabs open and, effectively, nothing else running and competing with it.

My personal experience is that 8GB has been a practical minimum for Windows 10 since it came out. Despite the claims to the contrary. Yes - I know you can run it on less but it is often not very happy. I was for a time running a 4GB Surface and changed to a very similar spec. with 8GB (after a replacement due to a hardware issue with the screen). The difference was even greater than I expected - and I knew to expect quite a jump.

I think there were issues in the last week or so - possibly due to some combination of Windows updates/Firefox/Office/something else. Seems fine now but for a couple of days had some odd issues. At least one Windows update appeared to have been re-released (assuming after it had been revised).