LezLezLez said

I am currently using Rel 60.0.2 but my old PC uses an Intel Pentium Dual CPU at 2.00 GHz with 4GBit of memory and W10 Pro Build 1803. The recent and current FireFox releases show either 4 or 5 threads running in memory and performance is very, very poor. I would like to consider reverting to a Release which does not require multi-core function. Is this R48? Where can i get it? is it supported? Does anyone have any other suggestion? Or will I have to consider another product/supplier?

HI, move to the Extended Support Release 60.0.2esr

• https://support.mozilla.org/en-US/kb/switch-to-firefox-extended-support-release-esr

Firefox ESR does not come with the latest features but it has the latest security and stability fixes.

You can disable multi-process windows in Firefox by setting these prefs to false on the about:config page.

• • browser.tabs.remote.autostart = false
  • browser.tabs.remote.autostart.2 = false

You should make a backup of your Profile before going back and just because:

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer

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

HI, also please : go to the Firefox 3 Bar Menu --> Options --> Privacy & Security panel and under Permissions check the setting to Prevent Accessibility Services from accessing your browser if it is not already.

Optimize Win10 :

• https://www.thewindowsclub.com/increase-page-file-size-virtual-memory-windows
• https://www.howtogeek.com/356642/how-to-fix-all-windows-10%e2%80%99s-annoyances/
• https://www.tenforums.com/tutorials/26120-optimize-performance-windows-10-a.html
• https://support.microsoft.com/en-ca/help/4002019/windows-10-improve-pc-performance
• https://www.windowscentral.com/15-tips-increase-performance-windows-10
• www.thewindowsclub.com/disable-visual-effects-windows

Maybe if not listed turn off Fastboot also.

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

You may see three or more Firefox processes running.

• one process for the main Firefox thread (user interface)
• one or more content processes set via dom.ipc.processCount
  Options/Preferences -> General -> Performance
  remove checkmark: [ ] "Use recommended performance settings"
• one process for the compositor thread (Windows;graphics)

You can find the current multi-process state on the Troubleshooting Information (about:support) page.

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

Thanks PKshadow and cor-el. I have followed your advice and am now running only one thread and performance is now very good. Thank you again.