core2duo cpu frequency scaling help

[tux99]

can someone please tell me what you have in /etc/modprobe.preload.d/cpufreq on a system with a Core2Duo cpu?

 

and the output of:

 

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors

 

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies

 

many thanks

Edited February 6, 2009 by tux99

[ianw1974]

From my system:

 

root@esprit:/home/ian# cpufreq-info 
cpufrequtils 002: cpufreq-info (C) Dominik Brodowski 2004-2006
Report errors and bugs to linux@brodo.de, please.
analyzing CPU 0:
 driver: acpi-cpufreq
 CPUs which need to switch frequency at the same time: 0 1
 hardware limits: 800 MHz - 2.00 GHz
 available frequency steps: 2.00 GHz, 2.00 GHz, 1.60 GHz, 1.20 GHz, 800 MHz
 available cpufreq governors: conservative, powersave, ondemand, userspace, performance
 current policy: frequency should be within 800 MHz and 2.00 GHz.
			  The governor "ondemand" may decide which speed to use
			  within this range.
 current CPU frequency is 800 MHz (asserted by call to hardware).
analyzing CPU 1:
 driver: acpi-cpufreq
 CPUs which need to switch frequency at the same time: 0 1
 hardware limits: 800 MHz - 2.00 GHz
 available frequency steps: 2.00 GHz, 2.00 GHz, 1.60 GHz, 1.20 GHz, 800 MHz
 available cpufreq governors: conservative, powersave, ondemand, userspace, performance
 current policy: frequency should be within 800 MHz and 2.00 GHz.
			  The governor "ondemand" may decide which speed to use
			  within this range.
 current CPU frequency is 800 MHz (asserted by call to hardware).

 

root@esprit:/home/ian# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors 
conservative powersave ondemand userspace performance 

root@esprit:/home/ian# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies 
2001000 2000000 1600000 1200000 800000

 

and one more command you can use:

 

root@esprit:/home/ian# cpufreq-set --help
cpufrequtils 002: cpufreq-set (C) Dominik Brodowski 2004-2006
Report errors and bugs to linux@brodo.de, please.
Usage: cpufreq-set [options]
Options:
 -c CPU, --cpu CPU		number of CPU where cpufreq settings shall be modified
 -d FREQ, --min FREQ	  new minimum CPU frequency the governor may select
 -u FREQ, --max FREQ	  new maximum CPU frequency the governor may select
 -g GOV, --governor GOV   new cpufreq governor
 -f FREQ, --freq FREQ	 specific frequency to be set. Requires userspace
					   governor to be available and loaded
 -h, --help		   Prints out this screen

Notes:
1. Omitting the -c or --cpu argument is equivalent to setting it to zero
2. The -f FREQ, --freq FREQ parameter cannot be combined with any other parameter
  except the -c CPU, --cpu CPU parameter
3. FREQuencies can be passed in Hz, kHz (default), MHz, GHz, or THz
  by postfixing the value with the wanted unit name, without any space
  (FREQuency in kHz =^ Hz * 0.001 =^ MHz * 1000 =^ GHz * 1000000).

 

for changing the settings. I don't have Mandriva, but the principals should apply the same.

[tux99]

thanks, I just got a Shuttle K45 (great very cheap little system, well worth its bargain price) with an E5300 (overclocked for now to 2.84 GHz) and was surprised that I only see 4 scaling frequencies:

 

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
2847000 2190000 1752000 1314000

 

while on my venerable trusty old P4 I get:

 

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
316658 633317 949976 1266635 1583293 1899952 2216611 2533270

 

So the new E5300 can only throttle from 100% to still approx. 40% and in only 4 steps while the P4 goes from 100% all the way down to 12% in 8 steps.

 

I would have expected the E5300 to be more scalable than the P4 rather than less, but your output seems to confirm that what I'm seeing is correct for a C2D class cpu.

Edited February 6, 2009 by tux99