Hi, Firefox now runs on all cores of your chip and now also has multi-thread capabilities. These show up as instances in Task Manager as do add-ons/Extensions. It sounds like they are preforming well as you mention nothing in the way of slowness, crashing or high ram values or system heat. Add-ons use about 20megs each of ram. As well instances for insecure sites and will add several for the Firefox Sandbox for protection these are no running in that. The controls for that are located here on 2nd heading but at same place of pic : https://support.mozilla.org/en-US/kb/performance-settings Options --> General --> Performance . Note: 1 = No Multiprocessor

A little old now, back from November last.

• https://www.howtogeek.com/332449/whats-new-in-firefox-quantum/
• https://developer.mozilla.org/en-US/Firefox/Multiprocess_Firefox
• https://www.howtogeek.com/334594/stop-complaining-that-your-browser-uses-lots-of-ram-its-a-good-thing/

If did not know :

• https://www.howtogeek.com/333110/how-to-customize-firefox-quantum-and-remove-the-white-space-around-the-title-bar/

Firefox can be customized around 235 million ways with usserChrome

• https://www.userchrome.org/what-is-userchrome-css.html

If need more information on usserChrome or help. ask.

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

Yes, it is running slower, as I stated in my post. CPU usage varies, from 44% to 90%, and RAM usage is usually above 75%.

Could the (12) be part of the active tab title? Some sites add (number) at the beginning of the tab title to let you know that changes or notifications have accumulated in that tab. You'll also see it when you hover the Firefox icon on the Windows 7 Taskbar.

Regarding the number of processes, that might not show on the Applications tab in Windows 7's Task Manager. You can check the Processes tab and click the "Image Name" column heading to sort all the firefox.exe's together to get a full count. 6-7 processes is pretty common if you have had at least 4 tabs open.