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On Wed, 31 Oct 2007 08:43:12 +0000 Clare Shepherd <clareeshepherd@xxxxxxx> wrote: > > Either way, that is no doubt the performance of a brand new battery. New battery, old battery, makes no odds. > > Given that they drop like a stone in fairly short order, after a few > > months you'll probably be lucky to get 1:15 - 1:30 out of it. > > > > As Simon says, 'unacceptably low'. Hence there is ongoing work to improve things. > Oh well, back to the drawing board. Thanks for the links Julian. > Seems the designer's brain was out to lunch re battery. The fault does not lie within the battery itself but within the software - specifically, the (usually proprietary) power management software. Work is ongoing to control how the kernel and the userspace applications cooperate to not waste CPU cycles and allow longer periods of time where the kernel is not constantly being woken up. The software must become power-management-aware in how it calls the CPU. Device drivers not pinging the kernel every microsecond to see if something has happened, applications not being such memory hogs that swap is always in use, applications and libraries supporting memory caches instead of writing to file every single time, etc.etc. When writing email, on IRC or viewing a webpage, the kernel should be almost completely inactive. Instead, it is often doing as much as at any other time during the operation of the laptop. As support improves, it is important to always have an updated kernel and updated applications. All the current software was developed primarily for servers or workstations with uninterruptable power supplies and mains electricity. It is only comparatively recently that other issues around laptops have been solved so that the software can now run on a device with limited power capacity. i.e. it's just a bug - and a common one at that. It is being dealt with as such. > When you > think of the battery life of the old Psions with much less > sophisticated batteries, it gives one pause for thought. > Clare Not really. Custom devices with custom software can handle specialised power management. General software on general purpose devices has not had to deal with the issue and the problems get worse simply because there are so many different people and tasks involved. It would be possible to create a laptop with much better battery performance but running a single "general purpose" application (e.g. almost anything in Gnome or KDE) could ruin all that work. Expect gradual improvement, sometimes held back by applications with a slower update cycle. -- Neil Williams ============= http://www.data-freedom.org/ http://www.nosoftwarepatents.com/ http://www.linux.codehelp.co.uk/
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