I use AMD Ryzen 9 5950X for my home NAS and want to save some power as my demand for CPU is mostly idle with big peaks.

ls -alh /lib/modules/$(uname -r)/kernel/drivers/cpufreq/

root@nas:~# ls -alh /lib/modules/$(uname -r)/kernel/drivers/cpufreq/
total 21K
drwxr-xr-x 2 root root  125 Aug 31 19:57 ./
drwxr-xr-x 1 root root   60 Sep 21 18:10 ../
-rw-r--r-- 1 root root 6.6K Aug 31 19:57 acpi-cpufreq.ko.xz
-rw-r--r-- 1 root root 2.1K Aug 31 19:57 amd_freq_sensitivity.ko.xz
-rw-r--r-- 1 root root 3.7K Aug 31 19:57 pcc-cpufreq.ko.xz
-rw-r--r-- 1 root root 6.7K Aug 31 19:57 powernow-k8.ko.xz

modinfo amd_pstate

root@nas:~# modinfo amd_pstate
name:           amd_pstate
filename:       (builtin)
license:        GPL
file:           drivers/cpufreq/amd_pstate
description:    AMD Processor P-state Frequency Driver
author:         Huang Rui <[email protected]>

watch -n 0.1 cat /sys/devices/system/cpu/cpu{0..$(nproc --ignore=1)}/cpufreq/cpuinfo_cur_freq

Every 0.1s: cat /sys/devices/system/cpu/cpu{0..31}/cpufreq/cpuinfo_cur_freq

4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000
4000000

https://forums.unraid.net/topic/134103-solved-modprobe-blacklisting-and-amd-p-state/

https://forums.unraid.net/topic/134103-solved-modprobe-blacklisting-and-amd-p-state/?do=findComment&comment=1223915

https://www.digitaltrends.com/computing/what-is-amd-smart-access-memory/

https://old.reddit.com/r/linux_gaming/comments/mp2eqv/if_you_dont_like_schedutil_and_what_its_doing/ https://old.reddit.com/r/Amd/comments/pbbqd0/cppc_enabled_vs_disabled/

URL: /Settings/Settings/Tools/Syslinux

modprobe.blacklist=acpi_cpufreq amd_pstate.shared_mem=1

nano /boot/config/go

Before

#!/bin/bash
# Start the Management Utility
/usr/local/sbin/emhttp &

mkdir /root/.ssh
chmod 700 /root/.ssh
cp /boot/config/ssh/authorized_keys /root/.ssh/
chmod 600 /root/.ssh/authorized_keys

After

#!/bin/bash
modprobe amd_pstate

# Start the Management Utility
/usr/local/sbin/emhttp &

mkdir /root/.ssh
chmod 700 /root/.ssh
cp /boot/config/ssh/authorized_keys /root/.ssh/
chmod 600 /root/.ssh/authorized_keys

“Unraid OS” - green

kernel /bzimage
append initrd=/bzroot modprobe.blacklist=acpi_cpufreq

It’s also possible from CLI

nano /boot/syslinux/syslinux.cfg

default menu.c32
menu title Lime Technology, Inc.
prompt 0
timeout 50
label Unraid OS
  menu default
  kernel /bzimage
  append initrd=/bzroot modprobe.blacklist=acpi_cpufreq
label Unraid OS GUI Mode
  kernel /bzimage
  append initrd=/bzroot,/bzroot-gui
label Unraid OS Safe Mode (no plugins, no GUI)
  kernel /bzimage
  append initrd=/bzroot unraidsafemode
label Unraid OS GUI Safe Mode (no plugins)
  kernel /bzimage
  append initrd=/bzroot,/bzroot-gui unraidsafemode
label Memtest86+
  kernel /memtest

nano /boot/config/modprobe.d/acpifreqdisable.conf blacklist acpi_cpufreq

nano /boot/config/modprobe.d/enableamdpstate.conf options amd_pstate shared_mem=1

only this works to not load default modprobe.blacklist=acpi_cpufreq append initrd=/bzroot modprobe.blacklist=acpi_cpufreq