I have some issues with high power usage when my computer is suspended. There is significant power drain from one day to the next, and the battery is completely depleted in three to four days when the computer is left suspended without being connected to a power supply. I currently run Ubuntu 20.04, and this was never an issue before upgrading or while I still used Windows. My battery broke down a few months ago, and my work place's IT department said they had never experienced a laptop battery breaking down after such short time (~2 years of use), indicating there are some issues with how Ubuntu manages battery usage.
I believe the battery drain issue started when I tried to fix another issue that arose when upgrading to 20.04, where my computer failed entering suspend mode. This page presented a fix, where the line
intel_idle.max_cstate=1 i915.enable_dc=0 is added to
/etc/sysconfig/grub. At the time, this didn't really prevent my computer from failing to enter suspend mode, but I still left the parameters there as it seemed to reduce the occurrences where suspend failed. Later suspend issue seem to have been fixed, while my computer still uses a lot of power while suspended, so I was trying to restore the setting to its original state. I believe the issue lies with
intel_idle.max_cstate=1 which prevents the processor from entering deep sleep states.
i915.enable_dc=0 disables GPU power management. I am not sure whether this will affect anything as my laptop seemingly only uses my nvidia GPU.
However, I have two issues here:
- I cannot find a file named
/etc/sysconfig/grub: There is no folder in
sysconfig, and there is no file named
grub. However, doing a search I did find a file
/boot/grub/grub.cfg, which contain the line
linux /boot/vmlinuz-5.4.0-77-generic root=UUID=901ebf90-3de9-4271-b1a3-c6ab7dec86c4 ro
quiet splash $vt_handoff. Are these the parameters I should modify? If not, where can I find the correct config file?
- I can no longer remember the original setting. What should the parameters be set to?
Alternatively, can there be another issue causing the battery drain on suspend?