I say - I think, not I rule out. There is difference (for me at least ). And because of that picture:
It seems to me not very logical even from Apple - cut down bandwith for some moment and then restore again. I think (again) that if PM is broken, its is broken all the time, not by random base. And if PM is broken, then some more problems will come up. I don't see any other problems related to power management.
I have too much computers, srry - I mistakenly give a wrong model and chip number, RTL chip is RTL8111E as I wrote initially.
About stupid question - no, I don't know how PM causes a delay of few dozens of microseconds, when traffic goes thru GB switch to computer next of it... that's why I asked about.
So, how that PM causes delay only when traffic is local? Why traffic from WAN is privileged and not affected?
Oh, this makes two stupid questions again . Not much... so there is more. What everyone needs to repair exactly in PM (for healty network)?
Sorry about questions, I live with Mac's start from 10.3 Panther, but I am first time in Sierra...