I’m putting together a home server running Ubuntu 22.04 LTS and I’m having a hell of a time with the c-states. Current power draw of the system is 33 watts but I’d like to lower that as far as possible. At the moment I can only get a C2 c-state. I’ve tried updating the kernel with HWE, I’ve tried turning off the sound and LAN in the bios, I’ve made sure the C packages are enabled in the bios, I’ve run a Ubuntu live USB with powertop –auto-tune and so far nothing has worked. My system is as follows:
- Motherboard: Asrock B660M-ITX/ac
- CPU: Intel i3-12100
- Storage: Intel 660p 1 TB M.2-2280 PCIe 3.0 X4 NVME Solid State Drive
- SATA Storage: Seagate Ironwolf NAS 6TB
- RAM: Corsair Vengeance LPX 16 GB CMK16GX4M2Z3200C16
- OS: Ubuntu 22.04.03 LTS, Kernel 6.2.0-26 generic
Some more info, don’t know if it will help
hsadmin@homeserver:~$ grep . /sys/devices/system/cpu/cpu*/cpufreq/scaling_driver
/sys/devices/system/cpu/cpu0/cpufreq/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpu1/cpufreq/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpu2/cpufreq/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpu3/cpufreq/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpu4/cpufreq/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpu5/cpufreq/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpu6/cpufreq/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpu7/cpufreq/scaling_driver:intel_pstate
hsadmin@homeserver:~$ grep . /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor:powersave
/sys/devices/system/cpu/cpu1/cpufreq/scaling_governor:powersave
/sys/devices/system/cpu/cpu2/cpufreq/scaling_governor:powersave
/sys/devices/system/cpu/cpu3/cpufreq/scaling_governor:powersave
/sys/devices/system/cpu/cpu4/cpufreq/scaling_governor:powersave
/sys/devices/system/cpu/cpu5/cpufreq/scaling_governor:powersave
/sys/devices/system/cpu/cpu6/cpufreq/scaling_governor:powersave
/sys/devices/system/cpu/cpu7/cpufreq/scaling_governor:powersave
hsadmin@homeserver:~$ grep . /sys/devices/system/cpu/cpuidle/*
/sys/devices/system/cpu/cpuidle/available_governors:ladder menu teo
/sys/devices/system/cpu/cpuidle/current_driver:intel_idle
/sys/devices/system/cpu/cpuidle/current_governor:menu
/sys/devices/system/cpu/cpuidle/current_governor_ro:menu
/sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us:0
/sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us:0
hsadmin@homeserver:~$ grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/name
/sys/devices/system/cpu/cpu0/cpuidle/state0/name:POLL
/sys/devices/system/cpu/cpu0/cpuidle/state1/name:C1E
/sys/devices/system/cpu/cpu0/cpuidle/state2/name:C6
/sys/devices/system/cpu/cpu0/cpuidle/state3/name:C8
/sys/devices/system/cpu/cpu0/cpuidle/state4/name:C10
hsadmin@homeserver:~$ grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/desc
/sys/devices/system/cpu/cpu0/cpuidle/state0/desc:CPUIDLE CORE POLL IDLE
/sys/devices/system/cpu/cpu0/cpuidle/state1/desc:MWAIT 0x01
/sys/devices/system/cpu/cpu0/cpuidle/state2/desc:MWAIT 0x20
/sys/devices/system/cpu/cpu0/cpuidle/state3/desc:MWAIT 0x40
/sys/devices/system/cpu/cpu0/cpuidle/state4/desc:MWAIT 0x60
In my bios I have enabled:
- Package C State Support
- CFG Lock
- C6DRAM
Prior to enabling them powertop showed no c-states being used, after enabling them C2 was being used.
Powertop image showing c-states
So I have no idea where to go from here. Perhaps the issue is with my NVME drive.
Also, there are some other settings in the motherboard that are disabled, could they be relevant?
- PCI Express Native Control - Select Enable for enhanced PCI Express
power saving in OS.
- PCIE ASPM Support - This option enables/disables the ASPM support for
all CPU downstream devices.
- PCH PCIE ASPM Support - This option enables/disables the ASPM support
for all PCH PCIE devices.
- DMI ASPM Support -This option enables/disables the control of ASPM on
CPU side of the DMI Link.
- PCH DMI ASPM Support - This option enables/disables the ASPM support for all PCH DMI devices.
Edit: I enabled the ASPM options and now powertop is showing that I am getting down to C3. Any idea what would be preventing me from getting to C6?
Edit2: I Decided to order a new SSD and RAM that are on the motherboard's list of compatible parts.
Edit3: New parts did not help. Have contacted Asrock to see what they say.
