Firefox 54 Promises Faster Browsing on Macs With Limited RAM

Mozilla yesterday announced the release of Firefox 54 web browser with new multi-process architecture that promises to make browsing with multiple tabs open faster and more stable, especially on computers with 8GB of memory or less.

With the latest release, Firefox uses up to four processes to run web page content across all open tabs. This means that a heavy, complex web page in one tab has a much lower impact on the responsiveness and speed of other tabs, according to Mozilla:
The old Firefox used a single process to run all the tabs in a browser. Modern browsers split the load into several independent processes. We named our project to split Firefox into multiple processes 'Electrolysis' (or E10s) after the chemical process that divides water into its core elements. E10s is the largest change to Firefox code in our history. Besides running faster and crashing less, E10S makes websites feel more smooth. Even busy pages, like Facebook newsfeeds, spool out smoothly and cleanly.


In Mozilla's own tests comparing memory usage for various browsers, it claimed that Firefox used significantly less RAM in macOS than both Safari and Chrome. The group has published an article on Medium explaining how the new E10s architecture works.

In one section titled "Why Chrome gets too hot when Firefox does not", Mozilla writes that Chrome's method of creating separate processes for each open tab can end up with each one consuming hundreds of megabytes of RAM, whereas Firefox reuses processes and content engines to limit memory usage.
By default, Firefox now creates up to 4 separate processes for web page content. So, your first 4 tabs each use those 4 processes, and additional tabs run using threads within those processes. Multiple tabs within a process share the browser engine that already exists in memory, instead of each creating their own.
Mozilla claims that Firefox's considerate memory usage means users with 8GB of memory or less can browse the web without the browser hogging resources, allowing them to do other things on their computer. Meanwhile, users with more than 8GB of RAM can bump up the number of content processes that Firefox uses to make it even faster.
To change the number of content processes Firefox uses, enter about:config in your address bar, and adjust the number for the dom.ipc.processCount setting (we'll be exposing a visible preference for this in an upcoming release).
Users can test out the claims by downloading Firefox 54 for free from the Mozilla website.



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29 months ago
Since when is 8GB considered low RAM for browsing?
Rating: 18 Votes
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29 months ago
It uses less memory because only a smaller part of the page is rendered.

Safari uses a little bit more of memory, but when you scroll, it's already rendered while on Firefox you have to wait...

Safari is better, also much better performance in JavaScript.

(https://postimg.org/image/6e1t7xf65/)
Rating: 6 Votes
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29 months ago
Nice to see Mozilla is continues to update Firefox. I often use it in combination with Safari (which rules on the Mac) and don't want to see us reduced to a webkit (or webkit forked - Google) mono-culture.

For those interested here is a plug-in compatibility checker for Firefox. If the Firefox installation detects that one of your plugins isn't multi-process compatible it won't enable multi-processing for Firefox on your Mac.

https://addons.mozilla.org/en-US/firefox/addon/add-on-compatibility-reporter/

Adblock and Ghostery were okay for me - but the User Agent Switcher was not, part of Firefox (so I can run more than one instance of Firefox on my OS X desktop with different settings - i.e. different users).

Checking "about:config" in the address bar (say Yes), then go to "dom.ipc.processCount" in the address bar to see how many multiprocess threads you're allocated. Should be 4 if everything is good.

Because of my OSX User Agent Switcher conflict I only have 1 for my processCount. The Windows version of task switcher is compatible, BTW. Mozilla needs to update the OS X version (and probably Linux - they often share alot of code) of the User Agent Switcher to be compatible as well.
Rating: 6 Votes
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29 months ago
firefox is dead, long live safari or chrome or even edge
Rating: 4 Votes
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29 months ago

Those are not "Macs", but "Macbooks" on the Apple site.

..... I still feel like you're joking here. A MacBook is not a Mac. Right.....
If that's the case, then Firefox's memory usage on it is a non-issue, since it's not "a Mac" and therefore won't run the "Mac" version of Firefox.

Also, those are iMacs, not Macs. That's how it works, right?

I guess the Mac Pro is also not "a Mac", even though its name suggest it's a Pro version of a Mac.

Please inform Apple, as their website's "Mac" header ('https://www.apple.com/mac/') is apparently wrong.

When I buy "a Mac" in your world, which model do I get?

Rating: 3 Votes
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29 months ago
So basically ALL Macs since none of them comes with more than 8GB!
Rating: 2 Votes
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29 months ago

Since when is 8GB considered low RAM for browsing?


*sigh*

Even seemingly static websites have become more complex than most local apps we're running. However, while Activity Indicator clearly shows wasteful apps, wasteful websites are hidden behind fat browser processes, so nobody in the industry optimizes their web site for RAM usage.

Browser tabs are literally taking hundreds of megabytes. (I'm looking at you Slack!)

At the same time, websites keep insisting on opening links in new tabs, so unless you constantly clean up behind yourself, you'll quickly find yourself with dozens of open tabs.

Go ahead and checkout how much your browser is really using. Chances are, you'll be surprised. (Use "View > All Processes, Hierarchically" to see all additional processes)
Rating: 2 Votes
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29 months ago


Looks like your plates are out of alignment.

Rating: 1 Votes
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29 months ago
I've used Firefox as my primary browser for over 12 years now on various platforms (mostly Windows and macOS/OS X). Mozilla's browser(s) once stood out with excellent support for web standards, though now that most people have caught up it's not that different among the major competitors. I still support Mozilla because they are the most "free" and open of the major competitors, and I support them philosophically in addition to believing that they put out a high-quality browser, albeit one that has had a few resource-hogging problem in the past. Chrome is pretty similar (even more so now that Mozilla is basically copying them--even removing their much more powerful add-on architecture in favor of Google's), but I still appreciate the open-ness of Firefox and don't think we should let any one particular browser become overwhelmingly popular again, lest we return to the "best in IE" (or Netscape) days.

PS - MacRumors, you're still using the old Firefox logo. They changed it about four years ago. This is the fourth major incarnation of the logo, but the it's pretty easy to differentiate from the previous two with the drastic reduction in glossiness: https://blog.mozilla.org/creative/2013/06/27/a-new-firefox-logo-for-a-new-firefox-era/
Rating: 1 Votes
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29 months ago
Nice. Now running with 4 processes enabled and multi-tabbed browsing does actually feel "snappier". ;) If you can't get it to work (check Activity Monitor for multiple "Firefox Web Content" processes), install Mozilla's Add-on Compatibility Reporter ('https://addons.mozilla.org/en-US/firefox/addon/add-on-compatibility-reporter/') and check if any of your extensions don't support multiprocessing.
Rating: 1 Votes
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