possible disk activity solution
You may have already figured this out, but I just happened upon this after resolving on my system, so figured I'd share the fix that worked for me. I noticed elsewhere that someone also had VMware on their Activity Monitor list. In my search, I found that many people were able to resolve the problem by dragging their Bootcamp partitions into the Privacy area of Spotlight (in System Preferences) - Spotlight (more specifically the mdworker function) goes nuts trying to index the Windows partition, which isn't possible since it's closed. So I decided to see if that goes for virtual Windows volumes as well, so I dragged my virtual machine volumes (had an older vmware volume that I haven't tossed yet, plus a newer Parallels volume) into Privacy in the Spotlight settings so they'd be off-limits for indexing, and now my 6-core is flying again, no more constant disk activity bogging it down. So might be worth giving that a try - good luck.