AMD Epyc 7452 on ASRock Rack ROMED6U-2L2T having CPU's base clock as max clock speed & not boosting?

[j.battermann]

I have an AMD Epyc 7452 CPU on an ASRock Rack ROMED6U-2L2T board running Proxmox 7 a linux system and running cpupower frequency-info reveals the following:

    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:  Cannot determine or is not supported.
      hardware limits: 1.50 GHz - 2.35 GHz
      available frequency steps:  2.35 GHz, 2.00 GHz, 1.50 GHz
      available cpufreq governors: conservative ondemand userspace powersave performance schedutil
      current policy: frequency should be within 1.50 GHz and 2.35 GHz.
                      The governor "ondemand" may decide which speed to use
                      within this range.
      current CPU frequency: 1.50 GHz (asserted by call to hardware)
      boost state support:
        Supported: yes
        Active: yes
        Boost States: 0
        Total States: 3
        Pstate-P0:  2350MHz
        Pstate-P1:  2000MHz
        Pstate-P2:  1500MHz

This CPU however is, according to its data sheet, able to boost to 3.35ghz, which I think I have never seen it do. In the Bios I can only set the Core Performance Boost to 'Auto' or 'Disabled' (it is set to 'Auto') and looks like this:

Is there anything I can do to get the CPU to boost to its (advertised) max clock speed and/or where could the culprit be.. is it the Bios that's causing this or is it a missing configuration somewhere in Proxmox / linux?

 

[ari2asem]

so far i know the max speed of epyc cpu's is for single thread on 100% load.

so, when you load cpu for more threads, then you will have speed that is somewhere between the lowest and max speed.

for multi-thread load you will never get the max speed

 

[j.battermann]

Yep that's clear, I have however never actively seen speeds north of 2.35ghz and I just stopped everything on the system and ran a couple of single thread benchmarks, and checking the core's frequencies continuously it always looks like this (so two cores run at 2.35ghz) and not one hz higher:

root@jBProxmox:~# cpufreq-info | grep "current CPU frequency"
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 2.35 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 2.35 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).
  current CPU frequency is 1.50 GHz (asserted by call to hardware).

 

[ari2asem]

more things to think about:
- what happens when you set the governer to Performance ??

- in bios: what are the settings under PERFORMANCE sub-menu of your screenshot ??

i dont have asrock board. but trying to help you ....
sometimes it helps when you set performance slider to POWER safe mode, in bios

Performance Tuning Guides - AMD

For a complete listing of tuning guides including AMD EPYC™ 7003 Generation Processors, please visit: https://www.amd.com/en/processors/server-tech-docs/search OS Tuning Microsoft Windows® Tuning Guide for AMD EPYC™ 7002 Series Processors VMware® vSphere ...

developer.amd.com

EPYC™ Resources - AMD

developer.amd.com

 

[j.battermann]

Much appreciated! setting the governor to 'performance' locked all cores to 2.35ghz, so not letting them step down to 2ghz or 1.5ghz and they were basically running at the max all-core frequency all the time. That's not my use-case however (the system runs a couple of VMs, one being a NAS but the other actual machines I work with and on throughout the day) and therefore the frequency and power usage etc should drop when unused and only clock up whenever needed.

The performance sub menu in the bios let's you override the three p-states ... so change the 1.5, 2.0 and 2.35 ghz steps, however that's done via messing with the voltages and one or two more parameters as far as I remember from earlier today, so more in the realm of 'overclocking' rather than just increasing the numbers and therefore I thought that was not the right thing to look for / at.

I'll go through the two guide (and the one SUSE posted) and check if / what might be missing and be wrong .. or maybe I am just not seeing it right.. Level 1 Tech's forums mention in a couple of threads that some Linux tools do not report the frequencies correctly. I'll keep this thread up to date what I'll find.

 

[ari2asem]

https://documentation.suse.com/sbp/all/pdf/SBP-performance-tuning_color_en.pdf