Firefox started using multi-core processors in ver 54 and has been a slow roll out and some plugins disable that until they are updated and you get a Firefox Update. So yes it is normal to see more than one now.

Highlight is Windows 10 letting you know what processes are using too much resources.

Yes using too much resources I would guess as between 2 am running 1600meg. Need to check my own Firefox.

Now if you had only checked the box to send date to Mozilla before posting I would not have to ask you to do these things.

Can you check on something please. Would you go to : Options => Privacy & Security => under 'Data Collection and Use' : Did you uncheck : 'Allow Firefox to install and run studies ' or is it checked  ? If it is checked uncheck it.

To check if you are enrolled in these studies : Type in the address bar about:studies Then Hit Enter

Any extensions that you see listed there, you can either disable or remove (at the end of the experiment they will be disabled anyway). See for further information : https://support.mozilla.org/en-US/kb/shield

Restart Firefox

If it is still hogging to much ram come back and will give you instructions on how to disable Multi-process.

Note : current version of Firefox is 56.0.1 Can Open Help then About and try to force it to update. Works only once per restart of Firefox (more or less) Note : Major update Firefox 57 Quantum release date Nov 14th https://www.mozilla.org/en-US/firefox/quantum/

Please let us know if this solved your issue or if need further assistance.

Thanks for you response.

Okay, so I unchecked that box, removed the extension and restarted firefox, and the problem hasn't gone away. Still using a lot of RAM. What now?

Current Firefox releases have multi-process windows enabled. You may see three or more Firefox processes running.

• one process for the main Firefox thread (user interface)
• one or more processes for content threads set via "Options/Preferences -> General -> Performance" (dom.ipc.processCount)
• one process for the compositor thread (Windows)

You can look at "Multiprocess Windows" and "Web Content Processes" to see the current multi-process state.

• "Help -> Troubleshooting Information" -> Application Basics:
  Multiprocess Windows
  Web Content Processes

See also:

• https://www.ghacks.net/2016/07/22/multi-process-firefox/
• https://www.ghacks.net/2016/11/11/firefox-52-nightly-quantum-compositor-has-landed/
• https://hacks.mozilla.org/2017/04/firefox-53-quantum-compositor-compact-themes-css-masks-and-more/

My default limit for content processes is 1. Should it be more?

No need to increase the content process count in case the default is currently set 1.

Firefox is still using too much RAM and because of this its getting stuck every few minutes. I still don't have a clear solution.

My multi-process state is enabled, should I disable it? How?

How much physical RAM do you have installed on your computer?

A RAM usage of around 500 MB (400-800) isn't extraordinary for current browser releases especially if you visit web pages that have a lot of images or keep loading extra content if you scroll the page. When it regularly gets over 1.5 GB and doesn't decrease when you close tabs then this needs to be checked.

There are buttons on the about:memory page to free memory and do some cleanup (garbage collection).

I have 8 GB of RAM. When I "End task" and then close tabs, only then does the memory drop below 1000 MB. Besides thats, its regularly over 1000, close to 1500 MB and it causes the browser to freeze for a few moments at a time.

Keep in mind that 64-bit application allocate memory in 64 bit blocks and thus can use twice as much memory as 32-bit applications. So you can compare 8 GB on a 64-bit computer with 4 GB on a 32-bit computer. Maybe consider to add more memory if you regularly reach this limit. 32-bit applications have a memory limit of just below 4 GB (some memory is usually reserved) whereas 64-bit applications have an unlimited memory space (128 TB).