This seems like a regression to me. With 4.4.6, the CPU spends a significant amount of time (50+ percent) in PC8 and PC6. With 4.6-rc3, it very rarely reaches even PC3 (and never anything deeper than that), and when it does the screen starts randomly blacking out for short intervals. This is on a ThinkPad T460 with an i5 6300u.
Regression from 4.4?