CPU Speed keeps changing

faulwurf

Hey Guys,

i got a vps in germany which has a strange behavior. The CPU Speed keeps changing. Is that normal?

model name      : Intel(R) Core(TM) i7-4930K CPU @ 3.40GHz
Fri Jan 23 11:26:35 MSK 2015
cpu MHz         : 2550.750
cpu MHz         : 900.000
Fri Jan 23 11:27:06 MSK 2015
cpu MHz         : 2550.750
cpu MHz         : 1050.000
Fri Jan 23 11:27:36 MSK 2015
cpu MHz         : 900.000
cpu MHz         : 900.000
Fri Jan 23 11:28:06 MSK 2015
cpu MHz         : 2175.000
cpu MHz         : 2550.750
Fri Jan 23 11:28:36 MSK 2015
cpu MHz         : 900.000
cpu MHz         : 2550.750
Fri Jan 23 11:29:06 MSK 2015
cpu MHz         : 2100.000
cpu MHz         : 900.000
Fri Jan 23 11:29:36 MSK 2015
cpu MHz         : 2550.750
cpu MHz         : 2550.750

Regards,
Faulwurf

wych

SpeedStep/Energy Saving etc.

https://wiki.archlinux.org/index.php/CPU_frequency_scaling

tomle

Yes it's normal.

MarkTurner

Disable cpuspeed:

/etc/init.d/cpuspeed stop

The force the governor to performance mode for each CPU/Core:

echo -n performance > /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

J1021

MarkTurner said: Disable cpuspeed:

It's a VPS

wych

@kcaj said:
It's a VPS

Ask the provider to do so, or just crank your usage up 24/7

MarkTurner

@kcaj - Duh! Well the thought was there

faulwurf

ok, thanks

xyz

But the 4930K runs at 3.4GHz with a 3.9GHz Turbo clock. SpeedStep usually floors at 1.6GHz. Also, the BCLK of these CPUs is usually 100MHz, so things step in increments of 100MHz, meaning the 2.55GHz reading is weird.

I suspect the host is doing some scaling on the VMs.