Editing a Post, 99% CPU?

You may be dealing with the dreaded mod_security when your posting or updating . see if it’s enabled on the server first, if your using antimalware software it may be trying to scan on save . ok that’s the easy try . the next is to turn off your plugins . wsiwig editors., seo plugins . caching plugins . they all can contribute to post updates becoming really slow.. this is a one-at-a-time kinda thing so it gets tedious.