CPU parking, windows 2012r2, with no hyper threading

The PowerCfg commands will disable opportunistic core parking. If the server’s firmware uses the logical processor idling interface to request that Windows park cores, they would still be parked regardless of power policy configuration. If you take a trace you can see if that’s what’s happening on the system:

Xperf -start MySession -on Microsoft-Windows-Kernel-Processor-Power

Xperf -capturestate MySession Microsoft-Windows-Kernel-Processor-Power

Xperf -stop MySession -d mytrace.etl

Opening the trace in WPA you should see a “Core Parking Cap State” graph. If the cap for a park node is less than the number of cores in the park node (count the number of set bits in the affinity mask in the Park Node column) then a firmware cap is limiting the number of unparked cores via logical processor idling.