[Silhouette]

I've heard Firefox is snappy again, though I haven't seriously used it myself, but the damage is done.

Firefox still doesn't isolate separate web pages in different tabs from each other and the main browser UI. If you open a group of tabs and one of the pages is slow to load, or later you have an AJAX request going on in some tab that takes a long time to get a response, your whole browser UI will often go into a trance.

In fairness, they are working to improve this, but Firefox is several years behind the curve in this area. Until this is fixed, it really hurts any benefits from otherwise useful features like having tabs and bookmark folders in the first place.

[Erunno]

I know I start sounding like a broken record for those who read my comments regularly in these kind of threads, but I always feel inclined to point out that Chrome's much-lauded architecture has clear limitations once you start to push it too hard. I'm certainly not a typical user as I exhibit heavy tab usage. And I've used Chrome for weeks at times as my primary browser so I've come to know its advantages and disadvantages. Web pages may be given their own processes but they are not completely isolated from the browser process (containing the UI) since they have to communicate in order for the user to have something to see and interact with. And there are bottle-necks in the browser process. With too many open, active tabs the interface starts to stall badly. And the memory usage goes through the roof which causes the OS to swap pages from other applications out of memory which really hampers performance of the entire system. Chrome is optimized for the common case (very few tabs) but it doesn't scale well (i.e. at all) beyond this.

Whatever Mozilla will do to lessen the impact of content on the interface, I hope that they won't go down the same disastrous path as Chrome and make the browser unusable for any use other than the browser is optimized for. Right now I can have ~100 tabs open with Firefox thanks to excellent memory usage (including suspending tabs) and an interfaces which scales well (Panorama, switch to tab, tab overflow, etc.)

But I can see why Chrome is so attractive for many users. If you stay within its comfort zone the responsiveness is extremely pleasant in day-to-day usage.

[Silhouette]

Just to be clear, I didn't say anything about Chrome in my GP post. In fact, basically every other browser is much better than Firefox in this respect, and has been for a long time now.

I do take your point about using tabs heavily and the limitations of some other browsers. I too will often use many tabs if I'm researching something or just browsing social news/comment sites like HN.

On the other hand, I typically load a tab group of about half a dozen such news sites a couple of times a day, and Firefox goes into a trance for quite a while every time until those pages have all finished doing their thing, so it's not exactly performing well with even a few tabs either.

[dbaupp]

Standard questions: Are you on the latest version? Do you have a lot of extensions? Does it exhibit the same behaviour in safe mode?

(I don't get the UI stalling for very long ever, and I have tens and tens of tabs open always.)

[Silhouette]

I'm on the release update channel on most of my systems, so primarily using Firefox 13 right now, but this has been a problem since forever.

As for the rest, I'm sorry but I'm rather unforgiving of the extension buck-passing dance these days. It may well be that this particular problem is caused by an extension, and no doubt if I went through the usual production of disabling things one by one, running safe mode, messing around with config pages and all that jazz, I could probably pin it down. But the bottom line is that it should not be possible for any extension to cause severe performance, reliability or security problems. If that can happen at all, then Firefox is demonstrably broken on an architectural level, and it really is as simple as that.

(Lest you think I'm being flippant: one of my many hats is "professional web guy", so I do have a whole bunch of test systems and I do use use every major browser regularly. I don't tend to criticise browsers on technical grounds unless I have either a reproducible bug or a repeated pattern of poor behaviour across multiple systems and an extended period of time. This is the latter.)

[dbaupp]

The Firefox extension system is extremely powerful, i.e. extensions operate at the essentially the same level as the original browser code, which allows for really useful extensions which can only work effectively at that level. Obviously this means that code in extensions can "break" Firefox just as much as code in the browser proper.

Configurability like this is always a trade-off between power/efficiency and safety/reliability: if you want to allow others to fundamentally extend your product so that the extension is efficient/fast, you're going to need to give them deep access. Firefox has chosen to be more to this side of the spectrum, Chrome/Opera/IE have chosen to be more towards the other.

So the extension "buck-passing" is valid: you should be complaining to the extension author who has a memory leak, or who is running an infinite loop (or whatever). After all, you didn't have to install it.

(That said, Mozilla has recently been putting significant amounts of effort into making it harder for extensions to be "bad".)

[Silhouette]

I do understand the choice Mozilla had to make between control/sandboxing and power/flexibility. I just think that, with the infinite wisdom of hindsight and a view from the cheap seats, it was the wrong choice, and now they're paying the price.

It is unfair to blame Mozilla for the resulting problems, just as it's unfair to blame Microsoft because someone wrote a virus that infects Windows machines. Unfortunately, as in that other case, the value of the platform would be extremely limited without the extra functionality built on top. Put another way, I don't have to install the few extensions I use, but Firefox would not be worth using anyway if I didn't have them. The bottom line is that the platform is part of what you experience as a user and the platform's weaknesses can undermine everything running on it.

That all said, it is also fair to say that Firefox has had its share of performance and reliability problems without any help from extensions, and the architectural limitations in terms of tabbed browsing are well known. It may be that the poor behaviour I've observed recently has been caused by extensions, but it may not. To be blunt, it's not realistic for the Firefox developers to expect your average end user to go through an extensive process of systematically testing their combination of extensions and all the other fun and games every time the performance drops. Most people simply aren't going to do that, and they're going to point at Firefox and say "Well, Chrome gets it right" or something instead. It's not fair, but you've got to play by the rules of the game.

[cpeterso]

The biggest challenge with per-tab processes (Firefox's Electrolysis or e10s feature) is maintaining add-on compatibility. Chrome didn't have add-ons at first and didn't need to worry about backwards compatibility (at the time).

Firefox is also working on per-tab event queues to improve UI responsiveness. In the meantime, I recommend Firefox users check out the experimental "Suspend Background Tabs" add-on. Written by the author of Adblock Plus, Suspend Background Tabs will pause JavaScript execution and timers for background tabs.

https://addons.mozilla.org/en-US/firefox/addon/suspend-backg...

[sp332]

On the plus side, you can have hundreds more tabs open in FF than Chrome for the same amount of RAM. And recent versions won't even load tabs you're not using, they act more like bookmarks.