High power utilization 19 vs. 18.3

[Perette]

I recently tried upgrading to LinuxMint 19, installing from the ISO. Afterward, I noticed my fan was running continually. At first, I dismissed it as hot weather, but then my battery life seemed poor too: about 3 hours, instead of 5+.

PowerTop shows that under LinuxMint 19 my laptop is drawing about 14-15 watts of power continually. Booting up off the the 18.3 install media, PowerTop reports about 7-8 watts. I've since reverted to 18.3, under which PowerTop similarly reports 6-8 watts. These figures support the observations about the fan and battery life.

My first suspicion is the video card. My ThinkPad E570 has both Intel and NVidia graphics. Under both OSes, allegedly I was using the Intel and the NVidia was shut off. However, /sys/kernel/debug/vgaswitcheroo/switch under 18.3 reports NVidia as "DynOff" whereas 19 reports "Off".

0:IGD:+:Pwr:0000:00:02.0
1:DIS: :DynOff:0000:01:00.0

Moreover, PowerTop's "Device Stats" show the NVidia Usage as 0% under 18.3, but indicated 100% under 19. Additionally, there's only a handful (7) of devices running 100% under 18.3, under 19 there were several more, suggesting it's not just the video hardware.

0.0% PCI Device: NVIDIA Corporation GM107M [GeForce GTX 950M]

Advice?

[Pjotr]

Might be a kernel issue with the 4.15.x.... Stuff like that is usually solved by waiting for the redeeming kernel update.