Capturing help from Brian in a message.
Windows 10 msconfig.com seems a little buggie,
https://www.youtube.com/watch?v=luGZC-5DeQA
In Boot tab, advanced options - (per video) it was only allowing selection of 2 cores, not the 16 cores that Device Manager showed. It seems that the solution is to select '1' in # of processors, Save, Reboot, then running MSCONFIG again all 16 cores appeared as an option. Selected 16 & saved, rebooted again. After that all 16 cores showed in Task Manager, benchmark went up to over 13,000.
FIXED!