使用cpupower设置AMD Ryzen 5 7640U CPU频率无效的问题求助

大家好，我在桌面版Ubuntu 22.04.3、23.10的常规版和低延迟版上都做了尝试，现在碰到一个棘手的问题：我需要给运行图像捕获进程的核心提高最低频率，因为这个进程对CPU时钟速度要求很高。

我用这条命令设置核心5的最低频率：

paul@box4x4:~$ sudo cpupower -c 5 frequency-set -d 3000MHz
Setting cpu: 5

但实际频率完全没变化，用cpupower -c 5 frequency-info查看结果如下：

paul@box4x4:~/profiler$ cpupower -c 5 frequency-info

analyzing CPU 5:
driver: amd-pstate-epp
CPUs which run at the same hardware frequency: 5
CPUs which need to have their frequency coordinated by software: 5
maximum transition latency:  Cannot determine or is not supported.
hardware limits: 400 MHz - 5.58 GHz
available cpufreq governors: performance powersave
current policy: frequency should be within 3.00 GHz and 5.58 GHz.
The governor "performance" may decide which speed to use
within this range.
current CPU frequency: Unable to call hardware
current CPU frequency: 400 MHz (asserted by call to kernel)
boost state support:
Supported: yes
Active: no

核心5一直停在慢得离谱的400MHz，我是不是操作方式有误？有没有其他不那么繁琐的工具或方法能实现这个需求？

另外我发现一个明显的异常：显示的最高频率是5.58GHz，这显然不对，我用的AMD Ryzen 5 7640U的最大睿频应该是4.9GHz才对。

我在Intel N100的机器上做了 sanity test，那边是正常工作的：

paul@cube:~$ sudo cpupower -c 3 frequency-info

analyzing CPU 3:
driver: intel_pstate
CPUs which run at the same hardware frequency: 3
CPUs which need to have their frequency coordinated by software: 3
maximum transition latency:  Cannot determine or is not supported.
hardware limits: 700 MHz - 3.40 GHz
available cpufreq governors: performance powersave
current policy: frequency should be within 3.40 GHz and 3.40 GHz.
The governor "performance" may decide which speed to use
within this range.
current CPU frequency: Unable to call hardware
current CPU frequency: 3.30 GHz (asserted by call to kernel)
boost state support:
Supported: yes
Active: yes

核心3能达到我设置的3.4GHz，虽然用watch grep "cpu MHz" /proc/cpuinfo监控时偶尔会显示低一点，但比AMD这边的情况好太多了。

备注：内容来源于stack exchange，提问作者Paul Jurczak