Friday, July 22, 2005

Cooling my Linux laptop (Updated ...)

I came up with a rule (ok.. now 3 rules) to keep my machine (HP NX9040, Centrino 1.6 GHz, 512MB RAM, 40GB Hard Drive) cool with 'cpufreqd' when on AC power. Usually what happens with the default configurtion is that 'cpufreqd' makes the machine stay cool (by reducing CPU frequency appropriately) and in power saving mode while on batteries and returns to full power + full CPU frequency mode on AC power.

This makes the machine heat up unnecessaryly even when it is idle.

By adding the rule below in the /etc/cpufreqd.conf file, right before the 'AC_on' rule, I managed to get my machine temp down by 10 degrees (yes... you read right) when it's idle :)

Add the new rule to 'cpufreqd' and restart the daemon. (/etc/init.d/cpufreqd restart)

What the rules do is, check the CPU utilization level and if it is below a certain percentge then send the machine to lo_boost/medium_boost/hi_boost profile, which brings the CPU frequency down to appropriate ranges as necessary.

Oh... make sure you turn off your fancy CPU hungry OPEN GL screen savers as well and revert to 'blank screen' to get the max temperature drop possible.

Laid back ....


# power down when AC and idle (utilization 70% to 100%)
# Author: Tyrell Perera
ac=on # (on/off)

# power down when AC and idle (utilization 30% to 80%)
# Author: Tyrell Perera
ac=on # (on/off)

# power down when AC and idle (utilization 0% to 40%)
# Author: Tyrell Perera
ac=on # (on/off)

# originally the only AC on rule ... replaced by the three above
# full power when AC
#ac=on # (on/off)


Wednesday, July 20, 2005

Laptop Power Optimizer for Linux

cpufreqd is a really cool power manager for your linux laptop. After getting my laptop and setting it to dual boot winXP and Linux, I noticed a 10 degree (centigrade) temp difference between windows and linux, linux being in the higher range.

After getting cpufreqd, they both run on virtually identical temperatures and the battery life is virtually same in both as well.

Thanks Bud for the pointer to this software :)

Changing the User Agent in Firefox

Interesting Firefox extension which allows you to change the Browser and OS identification sent by Firefox. After intalling, a menu appears under 'Tools', which allows you to do this.

Bottom line? I can access my HSBC internet banking from Linux now, which wasn't possble earlier :)

Thursday, July 14, 2005

Updating to JDK 1.5.0 on mepis

Mepis comes with the Blakdowns version of java, which is 1.4.2_04. I updated it with the latest JDK from sun as follows.

- Make sure you have execute permisions for the .bin file downloaded from sun

# ./your-downloaded-jdk.bin

# vi .bashrc

- Add the following two lines

export JAVA_HOME=your-new-java-home

export PATH=$PATH:your-new-java-home/bin

# su -

$ cd /usr/bin

$ rm java

$ ln -s 'your-new-java-home/bin/java' java

$ rm javaw

$ ln -s 'your-new-java-home/bin/javaw' javaw

Now you can test this with typing java -version on the shell

# java -version

java version "1.5.0"

Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-b64)

Java HotSpot(TM) Client VM (build 1.5.0-b64, mixed mode, sharing)


Well as it sems, these two are not doing well in case of laptops. Especially if you want to close the lid expecting the damn screen to be turned off by the OS.

One guy has posted a solution here. I haven't teste this on my laptop yet, but will try to do so soon.

Friday, July 08, 2005

Automatic USB detection and Mount

I managed to get my USB flash drive to automaticaly mount in Linux and the steps are below;

Get root first of all ;)

  • # apt-get install pmount hal udev
  • # vi /etc/default/hal and comment out the line found there (#DAEMON_OPTS=--drop-privileges)
  • # cd /etc/hal/devices.d
  • # ln -s /usr/sbin/hal 50-fstab-sync.hal
  • make sure you enable device icons in KDE (using control center -> Behaviour -> 'Device Icons' tab -> select 'Show Device Icons' -> Select all you want to be seen in the desktop)
  • restart the session

-- Thank you Anuradha and Bud for the research :)

Tuesday, July 05, 2005

Lap Top search ...

I've been searching for a laptop for the past few days. Came across several candidates 'Acer Ferrari' being the coolest thing I saw. But my mind is set on the HP NX9040 which has all the features I want and comes closer to my budget as well.

IMHO Intel Centrinos are a bit overpriced at the moment. But I need a laptop NOW and there you have it ....

Friday, July 01, 2005

Gosling on Java in it's 10th Aniversary

Some interesting facts from the creater on his creation at it's 10th aniversary.