Using win10 here, on i7 and integrated GPU, and had occasional peaks and performance meter was jumping up/down quite a bit even if project was paused. Above registry hack worked for me to some degree, but occasional peaks remained. After updating to 8.0.30 some occasional peaks still remained. After digging around I noticed that this problem could be related to GPU drivers.
Windows 10 update didn’t show any new drivers for GPU. So I checked for update for my HD4600 GPU driver directly on Intel’s site. It seems win10 just skipped several GPU updates, and kept older version. Surprisingly, after updating HD4600 with latest driver all is fine now, performance meter is almost not moving when playback is stopped, and is quite steady while playback is running. No more occasional peaking in red, even at lowest 32 samples buffer.
EDIT: One month after above update, although situation is much improved, I still get occasional peaking in red and audio glitches. I’m out if options, just waiting that it gets fixed hopefully as soon as possible.