Laptop CPU Overheating with Ubuntu?

The last couple days I’ve seen some strange behavior from my laptop. It has locked up twice and another time, as I was using it, all my apps started shutting down. Wanting to know what was going on I checked /var/log/messages hoping to see a big error. Nothing. I did see a bunch of stats getting spit out about cpu and memory temperatures. Here is a snippet:

May 28 00:03:30 hplaptop kernel: [4304902.136000] DMA32 per-cpu: empty
May 28 00:03:30 hplaptop kernel: [4304902.136000] Normal per-cpu:
May 28 00:03:30 hplaptop kernel: [4304902.136000] cpu 0 hot: low 0, high 186, batch 31 used:34
May 28 00:03:30 hplaptop kernel: [4304902.136000] cpu 0 cold: low 0, high 62, batch 15 used:52
May 28 00:03:30 hplaptop kernel: [4304902.136000] cpu 1 hot: low 0, high 186, batch 31 used:166
May 28 00:03:30 hplaptop kernel: [4304902.136000] cpu 1 cold: low 0, high 62, batch 15 used:51

The alarming thing is the high 186 entry. Could this mean my laptop cpu is overheating? One complaint about my laptop is the fan runs dang near 24×7. Any ideas how to better diagnose this?

This Post Has 9 Comments

  1. pete

    your laptop has dual cpu’s?

  2. pete

    maybe your cpu supports hyper threading. that could be why you are showing 2 cpu’s. you should be able to turn hyperthreading off in your bios. try that and see if you still overheat….

  3. Erik Weibust

    For the first time ever, the stupid Intel Inside stickers have been useful. My sticker reads… “intel inside, Pentium 4 HT”. So no, I don’t have 2 cpus, and yes, I do have hyper threading.

    My question is what will I lose if I disable hyper threading? How can I get hyper threading to work?


  4. pete

    yeah…i don’t know that hyperthreading would be the problem. just wondering if you see the same behavior if you disable it. total guess.

  5. Kirk

    I’ve not tried Ubanti but… the problem with most linux distro’s running on laptops is power management. You may want to check to see if there are drivers avaliable that can step down the CPU when it is not being fully utilized.

  6. Jeb

    I don’t believe Hyperthreading would cause a problem. Do you see the processor frequency fluctuating with load? Also, check your process list for powernowd.

  7. Erik Weibust

    Look at that. Jeb makes his first comment on my blog!

    To be honest I’ve not paid any attention to processor load and I don’t know what powernowd is. When I run sudo powernowd I get the following:

    powernowd: PowerNow Daemon v0.97, (c) 2003-2006 John Clemens
    powernowd: Found 1 scalable unit: — 1 ‘CPU’ per scalable unit
    /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq: No such file or directory
    PowerNowd encountered and error and could not start.
    Please make sure that:
    – You are running a v2.6.7 kernel or later
    – That you have sysfs mounted /sys
    – That you have the core cpufreq and cpufreq-userspace
    modules loaded into your kernel
    – That you have the cpufreq driver for your cpu loaded,
    (for example: powernow-k7), and that it works. Check
    ‘dmesg’ for errors.

  8. Nick Fishman

    Kirk is almost certainly correct. I used FreeBSD 6 on my laptop for several months, and could never understand why the fans ran nonstop on it, but sat silent on Windows. I finally figured out how to enable CPU stepping, and the problem disappeared.

    Ubuntu now comes with stepping enabled by default, but there might be a hardware issue preventing it from working with you. That’s definitely the problem though, so start there when debugging.

  9. erik

    Howdy Nick,

    Thanks for stopping by. You and Kirk are right, but my problem is my cpu doesn’t support CPU stepping. So this time it has nothing to do with Ubuntu.

    It’s funny you left a comment on this post as just this week I’m moving back to Ubuntu and having to “redo” all my tweaks I spent so much time learning the first time around.


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