The heavy hitters so far as slowdowns is hefty graphical eyecandy oxps.
No surprise there.
Curiously, they inflict more of a load on the CPU, than they do on the 1070.
This is something that has me scratching my head at times. Does the CPU load drop/halve when V-sync is set to Adaptive?
What maik says about core usage is correct. Is your CPU actually eight cores, or four cores/eight threads, btw?
V-sync adaptive plus tribuffer on mitigates the microstutter effect if the FPS falls below 60. That's magic that happens at the graphics card; the card is reaching into it's personal buffer memory to fill in the missing frames in a microstutter event. No effect on the CPU, though the card's memory speed may fluctuate a bit.
The CPU is an 8350, one of AMD's FX series chips. There's 8 actual cores on it, but they're assembled in modules. Two cores per module, with a cache and floating point unit in each module.
A different approach to achieve what Intel does with 4 actual cores that simultaneously run 4 virtual cores. Which approach works best is a matter of debate, and it's been debated to death all over the web already.