Same setup, but my Firefox leaks memory like a sieve. It will crash 2x a day easily.
That said, I also have LastPass installed, I am using uBlock instead of ABP (though uBlock uses less memory anyway), and I also have RES installed.
I have seen websites leak incredible amounts of memory. To some extent I don't even know how much it matters what browser is used, if the JS is bad enough.
That's your problem, right there.
I've been told that the main version of LastPass currently available from addons.mozilla.org has known problems that cause the browser to lock up and hang indefinitely.
Instead, if you click through to list all releases and select the latest 4.x version, those problems should all be fixed:
https://addons.mozilla.org/en-US/firefox/addon/lastpass-pass...
Anyway. I have Firefox with uBlock, on Archlinux. With JS disabled. 400MB, about a hundred tabs. I do recommend using it that way. I also have Chromium, for things that require JS - youtube, facebook and the like.
window.leakyArr = [];
function leakStuff() {
leakyArr.push("This is leaked" + Math.random());
}
setInterval(leakStuff, 100);