odd cpu entry

[hawklord]

can anyone explain why my cpu shows as 1ghz less than it should be,

 

and its only single core - as far as i am aware,

 

my cpu is a pentium 4 prescott, 3.4ghz 800fsb

 

if this is an issue, does someone know how to fix it

 

ta

[tux99]

You probably have cpu-frequency throttling enabled, which means the cpu will slow down when full power is not required and speed up and full load. This is a very good idea with your cpu, as the Prescott gets very hot otherwise.

 

run the following commands:

 

these will tell you min/max frequencies

cat /sys/devices/system/cpu/cpu?/cpufreq/cpuinfo_min_freq

cat /sys/devices/system/cpu/cpu?/cpufreq/cpuinfo_max_freq

 

this will tell you all available frequencies

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

 

this will tell you all available governors (throttling rules)

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

 

this will tell you currently used governor

cat /sys/devices/system/cpu/cpu?/cpufreq/scaling_governor

[hawklord]

ok, now i'm scratching my head,

 

my minimum frequency is 3000000, maximum is 24000000,

which i suppose is .3 and 2.4 ghz,

 

i have - ondemand conservative powersave userspace performance

 

and i am currently using performance,

 

so a rough guess is - somethings wrong,

 

i dual boot so i'm going to reboot into the bios and have a nosy, then boot into windows and have a see what that says

[tux99]

I agree something is wrong, 300MHz minumum seems fine as I had the same with my old P4, but the maximum is too low, maybe you need a bios upgrade as the cpu is not detected correctly?

 

Also you should use 'ondemand' as 'performance' means it will run always at full speed which generates lots of heat and uses considerably more power.

Edited October 14, 2009 by tux99

[hawklord]

its a new mobo with up to date bios,

the cpu is socket 775 - couldn't afford both new, so i bought a new mobo and upgrade the cpu later (using my old one)

 

but i have an unlocked cpu, the mobo had auto set the ratio at X12,

i've reset the ratio to X15, which gives me 3.0ghz (200 x 15, 800 fsb), i'll see how that goes and maybe raise it again to 17,

 

the temp at the moment is under 40 c, so i don't think i have an issue with that - but i'll keep an eye on it,

 

why is it showing 2 cores ?

Edited October 14, 2009 by hawklord

[scarecrow]

why is it showing 2 cores ?

 

Because you have hyperthreading enabled.

Do a

# modprobe | grep p4

You you get a module "p4-clockmod" as loaded, then unload it and blacklist it. That way you won't have frequency scaling.

Edited October 14, 2009 by scarecrow

[hawklord]

[daddy@localhost ~]$ sudo modprobe | grep p4
Usage: modprobe [-v] [-V] [-C config-file] [-n] [-i] [-q] [-b] [-o <modname>] [ --dump-modversions ] <modname> [parameters...]
modprobe -r [-n] [-i] [-v] <modulename> ...
modprobe -l -t <dirname> [ -a <modulename> ...]
[daddy@localhost ~]$

 

this is what i get

Edited October 14, 2009 by hawklord

[theYinYeti]

scarecrow probably intended to say “lsmod | grep…†instead of “modprobe | grep…â€.

 

Yves.

[tux99]

 

Do a

# modprobe | grep p4

You you get a module "p4-clockmod" as loaded, then unload it and blacklist it. That way you won't have frequency scaling.

 

Why would he want to do that? His problem was caused by a wrong multiplier setting not by frequency scaling.

On a P4 frequency scaling saves considerable amounts of electricity, I had it on 'ondemand' for years on my P4 machine.

At 2.4GHz you got 40C which is ok, but if you change it to 3.4GHz you will see the temperature go up noticeably without using frequrncy scaling. There is no drawback in using it, only advantages.

[scarecrow]

Yeah, my bad... "lsmod" is the proper command.

[hawklord]

ok then,

 

i've set the ratio to 200x15 which looks like its giving me a temp of around 44c - but i'll keep an eye on it for a while,

 

to change from performance to ondemand do i just edit

 

/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

 

also, is there any need to block hyperthreading - i thought it was an advantage to have it