Can't get the scaling right for this CPU

General system Kernel, boot, graphics & hardware
21

Thanks @Stephane for the suggestion!
I’m a away from that system at the moment. I’ll try your command as soon as I am back home.

22

Several months later…

I had just forgotten about this :blush:

Looks like Liquorix kernel gets the cpu scaling right for this cpu:

6.1.4-lqx2-2-lqx #1 ZEN SMP PREEMPT_DYNAMIC Sun, 08 Jan 2023 05:16:01 +0000 x86_64 GNU/Linux

analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.0 us
  hardware limits: 400 MHz - 2.00 GHz
  available frequency steps:  2.00 GHz, 2.00 GHz, 1.90 GHz, 1.80 GHz, 1.70 GHz, 1.50 GHz, 1.40 GHz, 1.30 GHz, 1.20 GHz, 1.10 GHz, 1000 MHz, 800 MHz, 700 MHz, 600 MHz, 500 MHz, 400 MHz
  available cpufreq governors: ondemand userspace performance
  current policy: frequency should be within 400 MHz and 400 MHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency: Unable to call hardware
  current CPU frequency: 1.80 GHz (asserted by call to kernel)
  boost state support:
    Supported: yes
    Active: yes

CPU:
  Info: model: Intel Core i7-8565U bits: 64 type: MT MCP arch: Whiskey Lake
    gen: core 8 level: v3 note: check built: 2018 process: Intel 14nm family: 6
    model-id: 0x8E (142) stepping: 0xB (11) microcode: 0xF0
  Topology: cpus: 1x cores: 4 tpc: 2 threads: 8 smt: enabled cache:
    L1: 256 KiB desc: d-4x32 KiB; i-4x32 KiB L2: 1024 KiB desc: 4x256 KiB
    L3: 8 MiB desc: 1x8 MiB
  Speed (MHz): avg: 612 high: 800 min/max: 400/2001 boost: enabled scaling:
    driver: acpi-cpufreq governor: ondemand cores: 1: 800 2: 800 3: 800 4: 500
    5: 400 6: 800 7: 400 8: 400 bogomips: 31999
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx

Not knowing much about kernel builds, is this because Liquorix is differently build somehow?
Would appreciate your explanations/comments.

23

thats the main difference. And that lqx uses ondemand instead of powersave.

1 Like
24

Thanks for the reply!
That explains it! Great!

Another thing I notice is the difference in cpu hardware limits between linux-zen and linux-lqx.

For linux-zen:

min/max: 400/4600

hardware limits: 400 MHz - 4.60 GHz

For linux-lqx:

min/max: 400/2001

hardware limits: 400 MHz - 2.00 GHz

Isn’t that odd?

25

I am not familiar with Intel CPU’s, but the different scaling drivers might handle boost/turbo frequencies differently.

1 Like
26

I have been watching the cpu frequencies for a while now with linux-lqx, acpi-cpufreq driver and ondemand governor.
Interestingly, even though, it says the cpu to have an upper hardware limit of 2.00 GHz, it seems to burst up to 4,6 GHz when needed.
I need to run the system for a while to be able to have a more accurate comparison between linux-lqx and linux-zen when it comes to performance and power consumption.

Thanks!