Boost Clock not working

davepl

Member
Sep 22, 2022
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Running 7.2 VE on a 16 core Xeon Silver 4216. All cores are stuck at 2100MHz at all times and never boost.

I'm running Win11 client in one session running Prime95 at 100% on all CPUs. But when I check the CPUs on the host, they're all at base clock.

I'm checking this in the HOST by using ssh to get into proxmox and then running cat /proc/cpuinfo and looking at the "cph MHz" field all of which are at 2100.

This is also true when it's just one or two cores. All cores on the host stay at 2100.

My expectation is that when a client is fully loaded the PVE host would boost-clock some of the cores up to 3.6 or whatever the CPU is capable of. What could I be missing or doing wrong?

Thanks!
Dave
 
Last edited:
try check with realtime monitoring "s-tui" (apt can install it)

edit:
Just tried on a Xeon 4210 10c/20t and check spec Turbo Boost is only available on 1 core @ 3,2GHz others run at 2,2GHz
with many cores :
watch -n1 "cat /proc/cpuinfo | grep MHz"
is better than s-tui
 
Last edited:
Regardless of load within the VMs, everything seems pegged to 2100.

very 1.0s: cat /proc/cpuinfo | grep MHz proxmox: Mon Sep 26 10:39:48 2022

cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.017
cpu MHz : 2100.000
cpu MHz : 2099.392
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.001
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.000
cpu MHz : 2100.008
cpu MHz : 2100.000
cpu MHz : 2099.997
cpu MHz : 2100.000
cpu MHz : 2099.917
cpu MHz : 2100.000
 
Did you checked the BIOS options? Atleast here with my older Xeons it will only boost if I allow it in BIOS.
 
Yup, it was a BIOS issue. SpeedStep and Turbo were enabled but power management was disabled, which is apparently a prerequisite. Thanks all!
 
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