Modify CPU minimum frequency?

Ask Fedora
1

Can I safely modify the minimum frequency to… 1GHz or similar?
In Windows my CPU goes down to 0.8 GHz or less when idle.

Ryzen 5 5600:

$ cat /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_min_freq
2200000
$ cat /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_max_freq
4467285

2

What is the output of inxi -Czxx?
I have 3 different computers with 3 different cpus.
One is 2200/4400, one is 1400/4000, and the laptop is 800/4500 for min/max frequencies.

I think the cpu itself determines what is min/max for that system.

These can be tweaked a little by overclocking methods, but I am not aware of any way to slow down the minimum. Someone else may have more relevant info.

3 
Info: 6-core model: AMD Ryzen 5 5600 bits: 64 type: MT MCP arch: Zen 3
    rev: 2 cache: L1: 384 KiB L2: 3 MiB L3: 32 MiB
  Speed (MHz): avg: 2384 high: 2800 min/max: 2200/4467 boost: enabled cores:
    1: 2218 2: 2200 3: 2250 4: 2239 5: 2799 6: 2200 7: 2200 8: 2800 9: 2501
    10: 2204 11: 2800 12: 2200 bogomips: 84002

Yes, it says min 2.2GHz, nonetheless why Windows can set it down to 0.8GHz at idle?

5

I don’t understand, why is nothing wrong?

grep MHz /proc/cpuinfo
cpu MHz		: 2197.223
cpu MHz		: 2199.601
cpu MHz		: 2200.000
cpu MHz		: 2178.722
cpu MHz		: 2192.174
cpu MHz		: 2200.000
cpu MHz		: 2194.894
cpu MHz		: 2196.241
cpu MHz		: 2200.000
cpu MHz		: 2186.409
cpu MHz		: 2200.000
cpu MHz		: 2200.000

cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_cur_freq
2180876
2188134
2200000
2195062
2200000
2144334
2198421
2198536
2198448
2177666
2192179
2186408
7

This means the current real freq could be 0.8GHz?
Is there a way to check it?

9

I noted from your inxi output that you have an AMD processor like I do in both my desktops. My laptop is intel. The intel (i7-9750H) in the laptop will idle down to 800 but the AMDs will not slow down that much.

10

Do you have a way of measuring power consumption? That’s the important thing, right? A lower nominal clockspeed doesn’t automatically mean that. If a processor can “race to idle” — that is, get what it needs to do done and then sleep — that might save more power overall than taking a longer time to do the same thing without sleeping.

11

Here some info:
https://wiki.archlinux.org/title/CPU_frequency_scaling
I would advice against doing that. Let the distribution take care of it, a too low base frequency introduces a totally unacceptable response latency of the computer. You are using your laptop in interactive mode, so it has to react when you press a button, not a second later, you won’t run a serious job for hours on it anyway.

1 Like