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5arge

Member

Registered: 2009-03-10

Posts: 13

CPUFREQ: no affect on cpu temperatures, and missing stepping values

OK,

It appears I've managed to get cpufreq "working" on my system, the problem is, no matter what governor or custom frequency (userspace), the temperatures remain constant: at the same temperature range as the highest available frequency.  More details a further down.  Here are the current relevant settings:

Motherboard: EVGA 780i (Bios version P08)
CPU: Q6600 (B3 stepping)
"cpufrequitils packages is installed"
From /etc/rc.conf: MODULES=(acpi_cpufreq cpufreq_ondemand cpufreq_conservative cpufreq_userspace)
& DAEMONS=(syslog-ng network netfs crond hal fam sensors arch32 cpufreq openntpd)
Commented out min_freq and max_freq in /etc/conf.d/cpufreq  (and ondemand is set as the governor)
Speed stepping enabled in Bios using TM1 and TM2 thermal controls

Using the "CPU Frequency Scaling Monitor" panel applet, I can see the frequency changing as CPU usage is increased.  Changing the frequencies through this applet as well as through cpufreq-set -g reflects frequency changes in both the applet and cpufreq-info.  So, from everything I know about cpufreq, it appears to be working, yet temperatures are constant, never varying outside of a "normal" range (1 degree C).

Now, for troubleshooting purposes, here are the temps observed at different frequencies, without cpufreq modules or daemon, and stepping disabled in the bios (note all frequency changes performed through bios):

3.2GHZ: 46.5 degrees Celsius
2.4GHZ: 39.5 degrees Celsius
1.6GHZ: 39.5 degrees Celsius  (why it's not less than 2.4GHZ temperature is beyond me)

These temps were taken without any significant load; me simply monitoring temps, not running any programs that aren't already loaded at start up/log on.  Here are the temps monitored using cpufreq with settings described above (note: all frequency changed performed via cpufreq governors):

3.2GHZ: 46.5 degrees Celsius
2.14GHZ: 46.5 degrees Celsius

after un-overclocking via bios

2.4GHZ: 39.5
1.6GHZ: 39.5

I don't even know if this is something I should be concerned about, however, I'm under the assumption this is not normal: cpufreq modifying the frequency SHOULD affect CPU temperatures.  It's been about a year since I last re-greased and reset my CPU fan (not stock), but even so, my symptoms do not lead me to believe that this is the problem.

Finally, I understand that cpufreq doesn't change frequencies by using the FSB, rather, it changes the multiplier.  The multipliers available in my board's bios are 6-9, however, cpufreq only reports the stepping values that correspond with multipliers of 6 and 9, but 7 and 8 are missing.  I would think the stepping values of 2.14, 2.49, 2.85, and 3.2 would be available, yet, only 2.14 and 3.2 are available.  This isn't my primary concern, but I find it somewhat puzzling (perhaps better taken up with cpufreq dev?).

I hope my long post has provided some useful information.  I'm sure I need to provide more, but I don't know what else to give.

Thanks for taking the time to read this.  Any help would be greatly appreciated.

Last edited by 5arge (2009-05-31 11:47:14)

R00KIE

Forum Fellow

From: Between a computer and a chair

Registered: 2008-09-14

Posts: 4,734

Re: CPUFREQ: no affect on cpu temperatures, and missing stepping values

As I see it the time you spend in 2.4GHz isn't enough to make a real difference (if you use the ondemand governor), plus at 2.4GHz the voltage that is being supplied to the cpu may be the same or close to the one used at 1.6GHz so the power dissipation will be close.

Also if you are not loading your cpu most probably there are some parts that are in standby via clock gating (or inactive because there is nothing to do) to minimize power dissipation.

Also the ranges of temperature you report seem to be ok so nothing to worry about I believe.

---

R00KIE
Tm90aGluZyB0byBzZWUgaGVyZSwgbW92ZSBhbG9uZy4K

5arge

Member

Registered: 2009-03-10

Posts: 13

Re: CPUFREQ: no affect on cpu temperatures, and missing stepping values

Sorry, I may not have been too clear in my original post.  My CPU is at 2.14GHz at least 95% of the time that it is on.  Considering that, I would like to have temperatures that are "normal" for that frequency (basically, around 39.5 degrees).  The problem is, when cpufreq is enabled, the temperature is the same at 2.14 GHz than at 3.2GHz: 46.5 degrees.  I don't know why I listed 1.6GHz as it is not possible to obtain this frequency while overclocked; I guess I thought it would be useful for troubleshooting.

I'm not exactly sure what you mean by the "clock gating" statement.  I understand the concept of clock gating, but all of the temperatures listed are when the cpu was as "idle" as possible under gnome and after startup apps are launched: with cpufreq, I get higher temperatures at 2.14GHz than I get at 2.4GHz without cpufreq.

I know these temps are nothing to worry about as they are idle temps, but when cpu is loaded, temperature increases to low/mid 50s (low 60s during stress tests).

To reiterate (in a much cleaner and concise manner):

What I get:

2.14GHz = 46.5 degrees
3.2 Ghz = 46.5 degrees

What I think it should be (and what I want):

2.14GHZ <= 39.5 degrees
3.2GHz = 46.5 degrees

Thanks for your input, and sorry if I wasn't clear.