My hp 6820s stays so cool! Thank You!

[innobits]

Hi,

My laptop was ventilating loud like half of a vacuum cleaner almost all the time before, especially at weird moments like running idle waiting for input on a command line... It was time to handle. I disassembled it completely, removed a 2 mm accumulated dense pack of dust between fan and heatsink and almost laundried the heatsink to get it totally clean. Aditionnally I mounted a resistor into the fan cable that makes the fan turn about 6 times slower and then I underclocked the cpu to 1.6 GHz via scaling_max_freq and undervolted it using linux-PHC (phc_vid 0 for 1.6 GHz runs just fine).

Now my laptop stays cool (65.0 - 68.0 °C while running boinc applications vs. 60-70 when idle before). Also I can now finally feel the heat flow out of the ventilation holes on the side whereas before it was damn ventilating but nothing came out. And the most important of all: My laptop is now almost totally quiet!! (Actually now, and only if I really pay attention I can hear the hard disk louder than the fan, ^^ to tell you how quiet it is. Everything just like in a new laptop right out of the package! (Before all the cooling problems eventually occur there. ^^))

So a great thanks to the linux-PHC team! This is a really great job. I'm so happy!

The technical details:
hp 6820s laptop with T7250 2 GHz processor (double core)
Running Ubuntu Karmic 10.04 amd64, kernel 2.6.32 and linux-PHC 0.3.2-10 (Still uncomfortable about having to compile kernel 2.6.35 in Ubuntu Maverick by myself, and adding all Ubuntu and linux-PHC patches manually. And I heard otherwise it won't work. But let's take a look at it some time later.)

Cheers

[innobits]

Hi!


I finally gave it a try to install linux-PHC (in my case phc-intel) on Ubuntu 10.10 as promised, and this was quite simple! Thank you very much for this awesome module!

Here are the steps I followed, and I'm sure listing the steps will help the beginners among us like me:

• make sure that you have maverick-updates in your sources list (so that you get the latest linux and linux-headers packages)
• sudo add-apt-repository ppa:linux-phc/ppa
• sudo apt-get update
• sudo apt-get install linux-generic-phc
• sudo apt-get install linux-headers-generic-phc
• sudo update-grub

• reboot on the newly installed kernel

• download the phc module "phc-intel-0.3.2-12-1" from http://www.linux-phc.org/forum/viewtopic.php?f=13&t=2
• extract it and go to the directory where it extracted
• copy or rename inc/2.6.34 to inc/2.6.35

• sudo apt-get install patch (if not already installed)
• make
• sudo install -m 644 -o root -g root phc-intel.modprobe /etc/modprobe.d/phc-intel.conf
• sudo mkdir -p /lib/modules/`uname -r`/extra
• sudo install -m 644 -o root -g root phc-intel.ko /lib/modules/`uname -r`/extra/
• sudo depmod `uname -r` -a
  (not using make install, because on my system it somehow installs in the wrong kernel version subdirectory of /lib/modules)

• now reboot and normally the module phc-intel will be loaded and acpi-cpufreq won't

• you can also decide to load some phc parameters at boot by adding some lines to /etc/rc.local. !warning! these are specific to my configuration, you should replace the values with your own ones:
  echo "0 21 0 0 0" > /sys/devices/system/cpu/cpu0/cpufreq/phc_vids
  echo "0 21 0 0 0" > /sys/devices/system/cpu/cpu1/cpufreq/phc_vids
  echo "1600000" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
  echo "1600000" > /sys/devices/system/cpu/cpu1/cpufreq/scaling_max_freq

Great Thanks to the linux-PHC Team!
Have a nice day!

[lio]

[*]copy or rename inc/2.6.34 to inc/2.6.35[/list]

So you don't use the acpi-cpufreq.c file from the new kernel and you loose changes made to this file during kernel developement, which can lead to serious issues as this file isn't in sync with the rest of the kernel stuff anymore and you will likely miss bug fixes, like memory leaks.

If you have a kernel for which there is no suitable patch, you have to copy the new acpi-cpufreq.c from kernel sources and adjust the patch accordingly. Or just have a look at http://www.linux-phc.org/forum/viewtopic.php?f=7&t=267 which provides up to date patches.

Dirk