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On Fri, Apr 6, 2012 at 1:05 PM, Frank Steinmetzger <Warp_7@×××.de> wrote: |
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> On Mon, Apr 02, 2012 at 01:22:50AM -0400, Walter Dnes wrote: |
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> |
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>> > > Hi, |
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>> > > |
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>> > > admin of a colo-center keeps complaining my server is going |
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>> > > a little over power-limit (which they have set as ~120W per |
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>> > > 24h/avg, while my server needs ~130-135W). So I need to find |
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>> > > a way to save at least those 15W, or I will be moved to |
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>> > > higher tarif (which means higher costs for server-housing). |
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>> […] |
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>> The following may seem obvious, but here goes... |
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>> |
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>> * remove unnecessary video cards, and drivers. Most colo machines |
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>> should do OK with just a text console running on the onboard GPU. |
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>> Dump all video driver stuff "/dev/agpgart (AGP Support)" and |
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>> "Direct Rendering Manager". This assumes you're not running X on |
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>> your colo machines. mc (Midnight Commander) is a great text-based |
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>> tool, along the lines of ye olde Norton Commander. |
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>> |
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>> * disable sound cards/chips in BIOS and remove drivers and kernel |
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>> support. |
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> |
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> As a follow-up question that’s been on my mind for a long time: can I always |
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> assume that when there is no driver loaded, the device is really (physically) |
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> off, so it doesn't use any power (at all)? Or are there exceptions to that |
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> rule (like hardware known to be buggy)? |
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The hardware will be energized, but won't typically consume as much |
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energy as it would were it under active use and load. |
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> My concern comes from having an |
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> ageing laptop whose battery I want to preserve as well as I can. |
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> |
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> In my case, that would be bluetooth, ethernet, possibly even the optical |
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> drive, and even the touchpad. I can switch the latter off using Fn+F9, which |
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> even works on the tty. But does that really switch it off, or does the kernel |
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> merely ignore its input then? |
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For wireless devices, I believe the radio is switched off if you use |
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the hardware or software switches, but controlling hardware would |
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still be energized. |
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For ethernet, you probably want the driver installed, so you can |
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access any power-saving modes available to it. (Ditto most other |
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things) |
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Regarding touchpad...no idea. |
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Most of this is probably very case-by-case. Check the kernel configs. |
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Perhaps even measure power consumption changes after doing things like |
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disabling devices via sysfs. |
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|
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-- |
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:wq |
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