Ubuntu On Sony Vaio FW Series

Well, Happy New Year! I guess this is the last post in this year, so let’s get our undervolting back with 2.6.27 kernels.

First of all go to phc.athousandnights.de and download 0.3.2 version of patch. Put this into directory where you have or will have kernel sources.

If you have not sources yet, do things like in the 4th step from the post about brightness:

sudo apt-get build-dep linux-source-2.6.27
sudo apt-get install linux-source-2.6.27
cp /usr/src/linux-source-2.6.27.tar.bz2 ./
tar jxvf linux-source-2.6.27.tar.bz2
cd linux-source-2.6.27

Put linux-phc-0.3.2-kernel-vanilla-2.6.26.patch.tar.gz in your current dir (linux-source-2.6.27) and unpack it, then patch the kernel sources:

tar zxvf linux-phc-0.3.2-kernel-vanilla-2.6.26.patch.tar.gz
patch -p1 < linux-phc-0.3.2-kernel-vanilla-2.6.26.patch

Now go into cpufreq module dir and compile it and then install new compiled version:

cd arch/x86/kernel/cpu/cpufreq/
make -C /lib/modules/`uname -r`/build/ M=`pwd` modules
strip --strip-debug acpi-cpufreq.ko
sudo install -m644 -b acpi-cpufreq.ko /lib/modules/`uname -r`/kernel/arch/x86/kernel/cpu/cpufreq

Now reboot and check for module success:

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

If you see voltage numbers then you can start optimizing voltages for your cpu or take mine as reference from the previous post about undervolting.

P.S. Fan almost stops at 40C and starts at 50C.

WARN: This is not work in Ubuntu Intrepid, check for updated guide.

Using this CPU Undervolting Guide, I have found lowest voltage for my CPU (Core2Duo P8400 2.26Ghz).

Using lowest voltage make your CPU eating less power from battery.

You need to compile acpi_cpufreq module with PHC patch enabled to control voltage steps.

Then you stress your system and search lowest voltage with stability CPU work.

If you have the same CPU, put this lines in your /etc/rc.local file:

echo "9:30 72:25 6:17 134:17" > /sys/devices/system/cpu/cpu0/cpufreq/phc_controls
echo "9:30 72:25 6:17 134:17" > /sys/devices/system/cpu/cpu1/cpufreq/phc_controls

Guide will help you to compile new module, but if you want to search voltages yourself, there is bugs related to this CPU, the script provided there propably not work. And if you need more instructions how to do it, just comment and i will write another post about it.