More than one process is normal for the current Firefox. http://www.ghacks.net/2016/07/22/multi-process-firefox/ Multi-process Firefox is codenamed "e10s". https://wiki.mozilla.org/Firefox/multiprocess Try to disable multi-process tabs in Firefox. You can disable multi-process tabs in Firefox by setting the related prefs to false on the '''about:config''' page. '''browser.tabs.remote.autostart''' = false '''browser.tabs.remote.autostart.2''' = false Type '''about:config'''<enter> in the address bar. If a warning screen comes up, press the '''I Accept the Risk''' button. At the top of the screen is a search bar. ------------------------ ''Kenparkyn [[#question-1233100|said]]'' <blockquote> Painfully slow after upgrade. </blockquote> [https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode Start Firefox in Safe Mode] {web link} by holding down the '''<Shift> ''(Mac=Options)''''' key, and then starting Firefox. A small dialog should appear. Click '''Start In Safe Mode''' (not Refresh). Is the problem still there? https://support.mozilla.org/kb/Firefox+is+already+running+but+is+not+responding https://support.mozilla.org/en-US/kb/firefox-slow-how-make-it-faster https://support.mozilla.org/en-US/kb/firefox-uses-too-many-cpu-resources-how-fix https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-ram https://support.mozilla.org/en-US/kb/firefox-hangs-or-not-responding