I have been using Linux Mint with Cinnamon for many years but decided to give Manjaro Linux with Gnome a try. Therefore I am new in this forum. The general setup has worked well but I am noticing significantly increased power consumption on Manjaro compared to Mint 20.3.
I have an Asus UX325 with i7-1165G7. In Mint the idle power consumption is ~4-4.5W. In Manjaro it is 6.5-8.5W. To exclude that it is due to the desktop environment (Gnome vs. Cinnamon), I have also installed Cinnamon on Manjaro but this shows a similarly increased power consumption.
I am using TLP with the same parameters configured in Mint and Manjaro. Powertop shows that the package C-states in Manjaro do not reach levels below C2 (pc2) even though the individual cores reach the deepest C7 stages for >>90%. The GPU reaches RC6. In Mint the individual cores reach the same levels but the package C-states go way below and reach C8 (pc8). I suspect that the failure to reach deep package C-states is the reason for the increased power consumption in Manjaro.
Unfortunately, I have not found a way to make the CPU reach deeper package C-states on Manjaro. I have compared the output of tlp-stat in Manjaro and Mint but do not see a difference. Kernel in Mint 20.3 is the HWE kernel (5.13 Ubuntu). Kernel in Manjaro is 5.15. I also tried 5.10 and 5.17 with the same result. I noted that Manjaro uses a newer microcode for the CPU but doubt that this is relevant.
I would greatly appreciate any suggestions on what may be incorrectly configured. Is it possible that the Mint/Ubuntu kernel has some optimisations that Manjaro is missing?
Please let me know if I should provide the output of any commands. I wanted to attach the output of tlp-stat on Manjaro and Mint but did not see a way to attach files.
my personal experience with the intel_pstate-governor is a disapointment. the idea is well, the practice of it is poorish. after switching back to the “original” governor-control the efficiency is far way better.
to do so edit /etc/default/grub and add “intel_pstate=disable” to the existing entries of GRUB_CMDLINE_LINUX_DEFAULT. you need sudo-rights to edit the file.
I have played around with all options available in tlp but could not get it into deeper package c states. I am getting more and more convinced that there may be something special in the Ubuntu kernel. I wonder if there is a way to install the Ubuntu kernel in Manjaro just to try it out.
no, the kernel are always the same. it’s just the setup and you can’t rely that these settings are preconfigured in the right manner if you run an rolling-release. in this case stable releases do a better job indeed.
Many thanks for the suggestions. I tried the suggested kernel parameters but no improvement.
I have tried to look carefully into all power management options but could not find any with a different setting than in Mint. As I can boot into both environments and compare, I could compare the settings. It is of course possible that there is an option that is not exposed in tlp and I do not know about.
Does anyone know about a documentation that lists ALL available power-relevant settings?
The other possibility is some background task in Manjaro that keeps the CPU busy and prevents deeper package C states. However, I noticed the increased power consumption even if Gnome is not active, i.e. when switching from the login screen to a terminal and running powertop. So, it would have to be a program that is independent of the Gnome environment. If anybody has a suggestion how to troubleshoot this, that would be great.
I think I have proven that it is the kernel itself!
I copied the Mint kernel, initramfs and modules from the Mint installation into Manjaro and manually edited the boot info in grub to point to these files. Then I verified in Manjaro that the Mint kernel was loaded:
uname -a ✔
Linux UX325 5.13.0-44-generic #49~20.04.1-Ubuntu SMP Wed May 18 18:44:28 UTC 2022 x86_64 GNU/Linux
Now powertop is back to ~4W power consumption and the package reaches C8 (pc8) C state. No other settings were changed.
I think this definitely proves that something is wrong with the Manjaro kernel. If it is a different default to Mint/Ubuntu, it could be fixed with a kernel parameter at boot. If it is some patch, however, I will have to return to Ubuntu/Mint. I am not sure if there is a way to figure this out…
Yes, I tried all non-realtime kernels that are available in the Manjaro Settings Manager: 5.10.117-1, 5.15.41-1, 5.17.9-1 and 5.18rc7 with the same result.
I did notice that there are some differences in the kernel .config file used for the build between Mint and Manjaro and some of these options relate to the CPU. For example:
< # CONFIG_GART_IOMMU is not set
< # CONFIG_MAXSMP is not set
< # CONFIG_X86_MCELOG_LEGACY is not set
> # CONFIG_PERF_EVENTS_AMD_POWER is not set
< # CONFIG_MICROCODE_OLD_INTERFACE is not set
> # CONFIG_X86_CPA_STATISTICS is not set
> # CONFIG_ACPI_APEI_ERST_DEBUG is not set
< # CONFIG_X86_SPEEDSTEP_CENTRINO is not set
> # CONFIG_PCI_CNB20LE_QUIRK is not set
> # CONFIG_X86_SYSFB is not set
< # CONFIG_X86_X32 is not set
If I understand this correctly, there are multiple parameters in Manjaro (lines indicated with <) that build modules (“m”) instead of including in the kernel directly (“y”). Maybe a relevant module is not loaded.