Hmmm, after some digging into this issue with Tim, we may have uncovered the culprit. It looks like the 'LanguageTool' LibreOffice extension is causing the high CPU load, not LibreOffice itself.
When installed, opening a large document will send LibreOffice's CPU usage skyrocketing. After a few minutes (depending on the size of the document), the usage does eventually drop back down below 5% again. When uninstalled, opening a large document inhibits a short spike in CPU usage, but quickly drops off. LangugeTool bug report: https://github.com/languagetool- org/languagetool/issues/1217?_pjax=%23js-repo-pjax-container ** Changed in: libreoffice (Ubuntu) Status: Incomplete => Won't Fix -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1825513 Title: High CPU usage when large document open To manage notifications about this bug go to: https://bugs.launchpad.net/df-libreoffice/+bug/1825513/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs