I see you posted in this previous discussion,
I have an MSI Nvidia GTX 670 graphics card which has never caused problems prior to C8. Does anyone else have same card on C8 without issues?
I take it you have tried just switching to internal i7 HD Graphics? just to eliminate your MSI GTX 670.
my system runs two monitors running off the internal HD graphics.
Although i do have omnisphere 2 and Komplete (and most of the usual suspects, mostly back to hardware these days though) I do not get unusal spikes with these or other plugins. I am running windows 7x64 pro so am not sure how much this will help you with a test my end. My system will be running completely different drivers to your windows 10 drivers. Also, my Audio hardware runs with latest RME drivers and is not USB.
Maybe get everything running bear bones, nothing plugged in except soundcard, keyboard mouse, and your ASIO driver at startup + internal graphics. see if anything changes. I take it hyperthreading is already enabled in your BIOS? it def’ should be. windows 10 also needs a load of useless background stuff turning off.
It is extremely frustating this sort of thing, let us know how you get on. Right now though i’m out of time…back to work.