User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0 Build ID: 20150630154324 Steps to reproduce: I'm using FF on a Win7 64-bit Lenovo T410 portable with 8Gb RAM and 4-core i5. AV is F-Secure. Win7 updates from MS are up to date. I just start FF (v.39) and watch the CPU utilisation in Task Manager with no other applications running. Actual results: About 30 seconds after starting FF, the CPU utilisation rises from a few percent to 30%+ and stays there for several minutes. On TaskMan's Processes tab, 27+% of this is attributed to "firefox.exe *32". Then it goes through alternating cycles of short periods of 1-2% utilisation before rising again to 27%+. This behaviour occurs regardless of how many tabs are open in FF and of what sites are open on the tabs. I've scanned the PC with F-Secure AV, SpyBot Search and Destroy and MalwareBytes premium, all of which are up to date. None of them finds anything of consequence, just the usual tracking cookie stuff which I allow them to tidy up. None of this has made any difference to FF's behaviour. I have rebooted the PC several times, but the behaviour continues. As noted in the summary, this has only started happening today. I am running the same FF version on another PC on my LAN and on that, FF has continued to behave normally. As noted Expected results: After starting up FF should settle down to a few % CPU like it usually does.
Is it reproducible: 1) in safe mode: https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode 2) with a fresh profile: https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles
Hi Martyn, I didn't managed to reproduce this issue on the latest release(42.0) nor the latest Nightly(45.0a1). User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:42.0) Gecko/20100101 Firefox/42.0 Build ID: 20151029151421 User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0 Build ID: 20151206030448 I've also tried to reproduce it on your specified version of Firefox(39.0), but the CPU load didn't jumped over 2-3%. User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0 Build ID: 20150630154324 Considering this and the fact that the reporter did not responded to Loic's info request, I will mark this bug as RESOLVED WORKSFORME. If you still encounter this issue, please feel free to reopen this bug or file a new one. Thanks, Paul.
Status: UNCONFIRMED → RESOLVED
Last Resolved: 3 years ago
Resolution: --- → WORKSFORME
It's better to close it as incomplete as the OP didn't reply (but still can do it). ;)
Resolution: WORKSFORME → INCOMPLETE
Hi Loic, Thanks for your suggestion. I will consider your opinion when triaging further bugs. Thanks, Paul.
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