View Full Version : Knoppix Power Management

Steven Hair
09-29-2004, 12:27 AM
Anyone know anything about how the knoppix power consumption relates to windows or DOS? Or just plain facts about Knoppix power usage or managment?

09-29-2004, 10:58 AM
Windows XP performs better here because power management hardware is better supported under win :-( It's all a matter of good drivers und good configuration which is not the case with Linux and some/a lot of mainboards/notebooks. I've spent a lot of time to configure my desktop and notebook to have good power management support. The standard Knoppix installation is very poor in this case. On my desktop (mainboard is MSI KT880 Delta) which supports mobile Athlon XP's is the power management feature not available at all. Exspecially in the case if you have a mobile version of an Athlon XP. The support for this lacks completely in Linux because there is no support for this in the kernel at all. I say "Linux" because this is not only the problem with Knoppix. In Windows you have tools like CrystalCPUID and others to control multiplikator, FSB and core voltage which are very great tools. These tools are availabe with source code and are licensed under the BSD license. I'm surprised why nobody has transferred these tools to Linux :-( BUT there is one tool for Linux which is very "cool", called athcool, which can be found here: http://members.jcom.home.ne.jp/jacobi/linux/softwares.html
READ compatiblity list! You system may crash when you use it! On my system it works very fine. So try it out when you have backuped all your important files.
I have modified my 1800+ Athlon XP to be a mobile one which works very fine now. I could decrease the power consumption of the whole desktop (without monitor and audio speakers) from 81W to 60,3W which is about 25% less. I used athcool (which decreases the power consumption to 62,3W) and modified the powernow-k7 driver to support my desktop platform and modified mobile Athlons. So here are my result:
athcool mult=3x mult=11,5
ON 60,3W 62,3W
OFF 65,7W 81W
Even with athcool ON the cpu fan stops because there is no need of it :-) and the CPU stays very "cool"
By the way under Windows XP I got no better results.
What I still miss under Linux is the possibility to change the FSB online.
The efforts described in this post may go too far for some people, but I think I have answered a lot of questions in this thread and gave some useful hints. If somebody is interested in the modified powernow-k7 driver then drop a post here. I will reply. But I have to say that the modification is a very cheap hack.
1) I would have to spend some time to make the hack better and more flexible
2) You should have some experiences in driver programming

Cheers, Martin

Steven Hair
09-29-2004, 03:04 PM
Thanks Martin this helps a ton. Thanks again!