Lucid Netbook Remix power consumption optimization

[ophilar]

Hi. I'm trying to switch to Linux from Windows on my laptop. It's strong enough for Lucid Netbook Remix and I like this look and feel of this.

One huge disadvantage to Linux (so far) is power consumtion, from what I've seen - LNR need between 13-11.* Watts, while Win 7 needed between 15-10.5 Watts.

Difference is not that big, but could result in half an hour of additional work.

Powertop notifies mostly of plasma-netbook writing to a cache file on disk, preventing it from stopping and locking. Various other processes do the same.

How can I lower the power consumption in general? Specifically, how do I increase the time delay to write cache to disk and maybe retain more programs in RAM (Something like a RAM disk)?

Thanks

[Fintan]

I am no expert but google is a freiend:
http://forum.kde.org/viewtopic.php?f=66&t=84887&hilit=consumption

This may point you in the right direction.

[dibl]

I'm not sure I understand your math -- it looks like Windows runs the consumption both higher and lower, but it's not obvious that the net result is a "huge disadvantage".

However, you can slow down the journalling, swapping, and caching of the ext3 or ext4 filesystem. Of course the tradeoff (for journalling slowdown) is data security in the event of an unexpected power loss. Google "vfs_cache_pressure" and "vm.swappiness" and "vm.dirty_writeback_centisecs" and you'll find tips like these:

http://www.lesswatts.org/tips/disks.php

http://rudd-o.com/en/linux-and-free-software/tales-from-responsivenessland-why-linux-feels-slow-and-how-to-fix-that

http://duopetalflower.blogspot.com/2009/11/tuning-ubuntu-910-karmic-for-speed-and.html

http://ubuntuforums.org/archive/index.php/t-1178209.html

On my desktop system, which gets its power through a beefy UPS, I use these settings in /etc/sysctl.conf:


vm.swappiness=1
#
vm.vfs_cache_pressure=50
#
vm.dirty_ratio = 40
vm.dirty_background_ratio = 1
vm.dirty_writeback_centisecs = 12000

And I mount the drives with "noatime". But I don't do the writeback slowdown on my netbooks because of the data security risk.

Hope this helps.