Nice! Thanks for doing the test.
After some snooping I only had to disable internet + reboot (no difference unless reboot, I'm guessing whatever service has already started by then), to get my usual results back. Roughly 1.8ns difference for me.
I'm thinking it must be a new service/process native to 21H2. Have not had this happen from the first pre-release 11 build all the way to 21H1. Not sure what it is though, as my running services list is already very trimmed of unnecessary stuff, and I always bench with minimal background stuff. I didn't see anything in there, and nothing irregular is hogging CPU usage either.
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