[brazen1]

I didn't mean MPC-HC exclusively has slowed down.  So do other players.  Perhaps it's on my end although as part of troubleshooting I loaded an old system image prior to the slowness and other problems had manifested.  This occurs in Explorer running solo and in KODI being called.  One would think the call adds even more time.  In my case, older versions of madVR were faster, solo or called.  No idea why subsequent playbacks are quicker than 1st rounds for you.  Perhaps you (and I for that matter) are caching something somewhere we aren't aware of.  Have not looked at resource monitor and perhaps I should.

Thank you for explaining the BT.2020 adjustment.  Will make testing easier.  3 full movies so far.  No problems.  Yippy!

It didn't occur to me there could be dual tone mapping going on...  Do you think turning off HDR to the HDMI display port would eliminate one or is it going to dual tone map whether it's SDR or HDR anyway?

I'm not familiar with VapourSynth?  Should I be?

Ha!  No, my "logic" statement was not referencing your long post but alas your interpretation will lead to a more precise explanation in your thorough and useful bible, I mean guide.  The longer the better imo.  Thank you for all of them btw.  It's my midwestern blood and how it translates on paper.  (Yes, we hang our laundry on clotheslines, eat chicken legs with our fingers, and prefer sunny side up if we don't let em' hatch).  "I did read the logic..." meaning logic as in algorithm.

Thanks for the reply and info.  Always to the point and informative.