Firefox maybe too much for your System if it is a older system. Just because can run Win10 does not mean you should. Or it maybe a setting as you have only mentioned load times rather than taking up Ram.

Let us explore that 1st : Please : go to the Firefox 3 Bar Menu --> Options --> Privacy & Security panel and under Permissions check (put a tick in the box) the setting to Prevent Accessibility Services from accessing your browser.

You could try this please : Go the 3 Bar Menu then Options --> General --> Performance and untick everything. change the recommended size lower then see how it runs. Note: 1 = No Multiprocessor = slow again. Try 2 try higher go back try find sweet spot. Restart Firefox after making these changes please.

Note : Hardware Acceleration is for your Video Card, monitor to see if need to turn back on. https://support.mozilla.org/en-US/kb/performance-settings

As nothing came about what extensions you are using you can try this to see if a Extension is causing the issue : SAFE MODE

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

In Firefox Safe mode these changes are effective:

• all extensions are disabled (about:addons)
• default theme is used (no persona)
• userChrome.css and userContent.css are ignored (chrome folder)
• default toolbar layout is used (file: localstore-safe.rdf)
• Javascript JIT compilers are disabled (prefs: javascript.options.*jit)
• hardware acceleration is disabled (Options > Advanced > General)
• plugins are not affected
• preferences are not affected

TEST''''is issue still there ?

If wanting to roll back there is the Extended Release Version 52.7.4 ESR that maybe better for you : uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files , C:\Program Files(x86) & C:\ProgramData Then restart system. Then run Windows Disk Cleanup. (Note: This should be Pinned and run Weekly, If never done below expect 10's of gig's) Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do :

• 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

It will continue to get security updates until June 2018, and you can download and install it from this page:

• https://www.mozilla.org/en-US/firefox/organizations/all/

Note : Legacy Extensions will be deleted or removed in any version update after June 2018. Update : Firefox 52.9.0esr out on June 26 (same time as 60.1.0esr) will be the last major update for Firefox 52 ESR apart from any 52.9.x esr updates for security or allowed stability fixes.

Based on Quantum Firefox 60.2.0esr will be out Aug 21 and Firefox 52 ESR will be EOL then. So people will have to upgrade to 60.2.0esr to keep getting security updates if they have not manually upgraded to 60.x.o ESR already. Firefox 60 ESR will require Windows 7, 8, 10.

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

It is possible that your firewall or other security software blocks or restricts Firefox without informing you, possibly after detecting changes (update) to the Firefox application. Remove all rules for Firefox from the permissions list in the firewall and let your firewall ask again for permission to get full, unrestricted, access for Firefox and the plugin-container process and the updater process.

See:

• https://support.mozilla.org/en-US/kb/server-not-found-connection-problem
• https://support.mozilla.org/en-US/kb/Firewalls
• https://support.mozilla.org/en-US/kb/fix-problems-connecting-websites-after-updating

Try to start Firefox in Safe Mode to see if that works better.

• Windows: hold down the Shift key while starting Firefox
• Mac: hold down the Options key while starting Firefox

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode

let's address each of these: - latest 8th gen i7 (although with the latest FF update, runs like an 8088 trying to handle Win95) - hardware acceleration is on - safe mode is on - no extensions loaded

No, this is something going on with this release. Tuesday, FF worked perfectly. Wednesday, it sucked. Thursday, I gave up.

So does that mean you are not going to bother with doing and checking what I have suggest in paragraphs 2 to 4 ?

I did that, same result.

Try to disable accessibility services in Firefox.

• Options/Preferences -> Privacy & Security -> Prevent accessibility services from accessing your browser
• https://support.mozilla.org/en-US/kb/accessibility-services
• http://techdows.com/2017/08/firefox-57-prevent-accessibility-services-accessing-browser.html

See also:

• https://support.mozilla.org/en-US/kb/quick-fixes-if-your-firefox-slows-down