What Is Firefox Process Priority Manager and How You Can Turn It Off

[The AchieVer]

What Is Firefox Process Priority Manager and How You Can Turn It Off 

As the only one major alternative to the avalanche of Chromium-powered browsers, Firefox has no other option that to keep evolving with every new release, and parent company Mozilla knows this best.

 

The next updates for the stable branch of Firefox, for example, is projected to bring new capabilities, including a so-called Process Priority Manager supposed to land in version 69.

So what exactly is the Process Priority Manager?

Technically, this feature is supposed to optimize the browser in a way that would allow the operating system to prioritize resources for the active tab. In other words, if you’re browsing the web with 5 different tabs in Firefox, more resources would be directed to the tab you’re currently in, thus allowing Firefox to render the content on that page with no performance hiccup.

For better understanding, imagine that you’re browsing five different websites called 1, 2, 3, 4, and 5. When 5 is the active tab, 1, 2, 3, and 4 become background processes that use a certain amount of resources even if you’re not viewing them.

With this new feature, the operating system would be able to direct some of the resources used by websites 1, 2, 3, and 4 running as background processes in order to increase the performance of page 5 in the active tab. This way, regardless of the content on page 5, Firefox should provide flawless performance all the time.

Mozilla says that background tabs with media content would be ignored, leaving all their resources untouched in order not to interrupt the playback. This means that if you’re listening to anything on YouTube in a background tab, Firefox’s Process Priority Manager wouldn’t redirect its resources.

 

 

 

Mozilla has already conducted a series of tests to determine the performance boost produced by Process Priority Manager, and the results aren’t necessarily impressive.

“According to our Beta experiment, the process priority manager had no measurable impact on page load time, tab switch time, or user retention. So, the good news is that it doesn't appear to make things worse. However, I'm a bit sad to say that it also didn't appear to make things better (via the probes that we measure). We do know, however, that lowering background tab process priority allows the OS to prioritize work in foreground tabs. So at the very least, this should be a resource usage win,” a company engineer said.

While the performance increase is minimal, Mozilla seems to be ready to ship this feature to all users with Firefox 69. So as part of the company’s effort to bring this to the stable channel of the browser, Process Priority Manager was enabled by default in the latest version of Nightly.

To try it out, you must be running Firefox Nightly 69.0a1 (2019-06-02) (64-bit). But because no substantial boost is produced and the feature brings more benefits to low-resource devices, you can very well disable it at this point.

To do this, open Firefox Nightly, and in the address bar of the browser, type the following code:

about:config

Next, you need to use the search box at the top of the screen to find this flag:

dom.ipc.processPriorityManager.enabled

By default, it ships set to True, so you need to double-click it to switch it to False. This means that:

True = activated
False = disabled

A reboot of the browser isn’t required.

Firefox 69 is projected to launch on September 3, so it remains to be seen if Mozilla plans to make any other changes to the Process Priority Manager feature in the meantime.

 

 

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