my browsers hate my Mac

[cellio]

For the past couple weeks -- but not before then -- both Firefox and Chrome have been randomly seizing up on me on my Mac at home (running Snow Leopard). When this happens, first that application and then (about 10-15 seconds later) the entire machine become unresponsive, presenting the spinning beachball of doom. After a minute or so, but occasionally longer, things go back to normal. Sometimes I see a Chrome pop-up about an unresponsive site flash by. When this happens and I can watch in the Activity Monitor, neither CPU nor memory is pegged. Sometimes this happens once a day; sometimes it happens a couple times in an hour. It's becoming a pretty big usability problem.

All browsers are up to date (and not beta versions). This doesn't happen on my work machine (Win7). Dani says this happens to him on his brand-new iMac with maxed-out memory, but only with Firefox. (So he uses Chrome -- problem solved.) For me on my dusty old Mac Mini, it's happening with both browsers. I can't figure out what changed -- why is this happening now?

Googling told me that disabling the Flash player extension/addon/plugin/whatever could fix this, but it didn't. I've also looked through extensions and disabled anything I'm not actively using; it's pretty bare-bones. I do have several userscripts, none written by me, but I don't see anything glaringly suspicious in their code. I've already disabled the ones I can live without at least for a while, but a couple of them really are critical. I'm not finding any help on the Apple forums.

I've been thinking about upgrading my hardware anyway, as even before this started my Mac was starting to get sluggish sometimes. I bought it in something like 2009, so that's not too surprising. But the Mini hasn't been updated since October 2014, so this is the wrong time to buy -- something better should be coming before too much longer.

Meanwhile, I'd like to diagnose and fix this problem. But I'm out of ideas. :-(

Comments

[cellio]

Processor temperature -- interesting. I would not have thought of that, or that I could monitor it, at all!

Thanks for the hint about JS-heavy tabs. I'd noticed that more tabs seemed to degrade performance but didn't make the connection that what's going on in those tabs is the real key. I mean, I usually have a bunch of LJ tabs open, but that's static content -- shouldn't matter, right?

I've been using NoScript on Firefox for years. Granted there are sites I've whitelisted and it's annoying when you hit a site that uses a ton of third-party JS and you have to sort through it, but it's still worth it to me. "Temporarily allow all this page" means "pretend I'm not using this extension in this tab", so in that sense it's not worse than just not using it, I figure. (Modulo a few extra mouse clicks.)

[siderea]

I mean, I usually have a bunch of LJ tabs open, but that's static content -- shouldn't matter, right?

The LJ homepage seems to be a culprit. Regular pages mostly seem fine, but I don't use the new friends feed, so I'm not sure how well that performs.

[cellio]

I meant individual pages -- posts I intend to read/comment on/monitor later. And I don't use the new friends feed either; I hated it when I looked at it and the old one works fine, so I haven't invested any effort in the new one.

Oh, another thing I should have mentioned: I have Firefox set to not load a tab until I actually visit it. (I don't know how to do that in Chrome.) If you're not doing that and you're seeing problems at browser launch, look for that setting in the preferences. I wish I could also tell browsers not to refresh a tab until I go to it; that would presumably help with the JS-heavy-sites problem.

[siderea]

If you're not doing that and you're seeing problems at browser launch, look for that setting in the preferences.

I don't have that set (I want pages to load in the background, so they're ready to read when I get around to them), but I don't have a problem at browser launch. It's only after the brower's been open a while (usually).

I wish I could also tell browsers not to refresh a tab until I go to it; that would presumably help with the JS-heavy-sites problem.

Yes, that might help a lot. Also, if I leave a page, I generally want it in the state I left it. Or at least, I'd like the option of not having it update itself.

[cellio]

"Leave it in the state I left it" would be my preferred browser directive, too. Let me decide when to refresh a page!