CPU power management issue

General
1

Hi,
Here are the specifications of my computer:

  • RAM: Corsair Vengeance RGB RT, DDR4, 32 GB (2 x 16 GB), 3600MHz, CL16
  • Motherboard: MSI MAG B550 TOMAHAWK MAX WIFI
  • Fans: be quiet! Light Wings LX 140mm PWM High-Speed (3x at the front, 1x at the back)
  • Processor: AMD Ryzen 7 5800X (Undervolted, running at a fixed 4400 MHz on 1.17500V)
  • Cooling: be quiet! Pure Loop 2 FX 240mm (Mounted at the top of the case)
  • SSD Heatsink: be quiet! M.2 MC1 Pro
  • Storage: Samsung 990 Pro 1 TB
  • Case: Kolink Citadel Mesh ARGB (Version that supports E-ATX motherboards)
  • PSU: MSI MPG A850G PCIE5 850W
  • GPU: Gigabyte GeForce RTX 4070 WindForce OC 12GB

After installing CachyOS with KDE, when I open “Power Management” from the taskbar, it says that it’s not available. There’s no slider to adjust the CPU performance mode. Adding amd_pstate=active to GRUB didn’t help.

How can I fix this?

2

can you check

cpupower frequency-info
sudo journalctl -b0 | grep 'amd'
3

@stephane

❯ cpupower frequency-info

analyzing CPU 13:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 13
  CPUs which need to have their frequency coordinated by software: 13
  maximum transition latency:  Cannot determine or is not supported.
  hardware limits: 2.20 GHz - 4.40 GHz
  available frequency steps:  4.40 GHz, 2.80 GHz, 2.20 GHz
  available cpufreq governors: conservative ondemand userspace powersave performance schedutil
  current policy: frequency should be within 2.20 GHz and 4.40 GHz.
                  The governor "schedutil" may decide which speed to use
                  within this range.
  current CPU frequency: Unable to call hardware
  current CPU frequency: 4.40 GHz (asserted by call to kernel)
  boost state support:
    Supported: yes
    Active: no

~
❯ sudo journalctl -b0 | grep 'amd' 
sty 11 18:18:39 pc kernel: Command line: BOOT_IMAGE=/@/boot/vmlinuz-linux-cachyos root=UUID=2c80824f-5e5b-4991-8a12-f81b0ab5f927 rw rootflags=subvol=@ nowatchdog nvme_load=YES zswap.enabled=0 splash loglevel=3 amd_pstate=active
sty 11 18:18:39 pc kernel: Kernel command line: BOOT_IMAGE=/@/boot/vmlinuz-linux-cachyos root=UUID=2c80824f-5e5b-4991-8a12-f81b0ab5f927 rw rootflags=subvol=@ nowatchdog nvme_load=YES zswap.enabled=0 splash loglevel=3 amd_pstate=active
sty 11 18:18:39 pc kernel: perf/amd_iommu: Detected AMD IOMMU #0 (2 banks, 4 counters/bank).
sty 11 18:18:39 pc kernel: amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled
sty 11 18:18:40 pc kernel: kvm_amd: TSC scaling supported
sty 11 18:18:40 pc kernel: kvm_amd: Nested Virtualization enabled
sty 11 18:18:40 pc kernel: kvm_amd: Nested Paging enabled
sty 11 18:18:40 pc kernel: kvm_amd: LBR virtualization supported
sty 11 18:18:40 pc kernel: kvm_amd: Virtual VMLOAD VMSAVE supported
sty 11 18:18:40 pc kernel: kvm_amd: Virtual GIF supported
sty 11 18:18:40 pc kernel: amd_atl: AMD Address Translation Library initialized

~
❯
4

is cppc active in your UEFI motherboard ( advanced cpu )?

1 Like
5

I have this option in UEFI, but I turned off CPPC.

6

@stephane
I enabled CPPC in the UEFI, and the problem was resolved. Thank you for your help!!

7

in this case , amd-pstate or amd-pstate-epp cant be used , it failback to acpi-cpufreq.

takes all info screen for your cpu ( Volt , etc , ) , because if your active cppc , it may changes others values

from mine

cpupower frequency-info
analyse du CPU 9 :
  driver: amd-pstate-epp
  CPUs which run at the same hardware frequency: 9
  CPUs which need to have their frequency coordinated by software: 9
  maximum transition latency:  Cannot determine or is not supported.
  limitation matérielle : 550 MHz - 4.65 GHz
  régulateurs disponibles : performance powersave
  tactique actuelle : la fréquence doit ÃÂȘtre comprise entre 550 MHz et 4.65 GHz.
                  Le régulateur "performance" est libre de choisir la vitesse
                  dans cette plage de fréquences.
  current CPU frequency: Unable to call hardware
  current CPU frequency: 550 MHz (asserted by call to kernel)
  boost state support:
    Supported: yes
    Active: yes
    AMD PSTATE Highest Performance: 176. Maximum Frequency: 4.65 GHz.
    AMD PSTATE Nominal Performance: 132. Nominal Frequency: 3.70 GHz.
    AMD PSTATE Lowest Non-linear Performance: 62. Lowest Non-linear Frequency: 1.73 GHz.
    AMD PSTATE Lowest Performance: 20. Lowest Frequency: 550 MHz.

in amd-pstate-epp be careful there is value power and cpu scheduler
you have only powersave or performance

if you want amd-pstate=passive or active you need to put this parameter to boot kernel

you have these options
conservative ondemand userspace powersave performance schedutil

in both case frequency cpu can varying from 400ghz to max 4,65ghz

1 Like