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On Feb 19, 2008 12:09 PM, Florian Philipp <lists@f_philipp.fastmail.net> |
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wrote: |
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|
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> |
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> On Tue, 2008-02-19 at 11:28 +0100, b.n. wrote: |
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> > Lowe Schmidt ha scritto: |
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> > > Hi. |
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> > > |
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> > > I'm planning on buying myself a MacBook and I'm just wondering if |
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> anyone |
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> > > knows how many hours I will get out of it if I run Gentoo. I mainly |
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> use |
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> > > a bunch |
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> > > of terminals, gvim and some lightweigth gtk app so nothing heavy going |
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> on. |
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> > > |
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> > > All input appreciated |
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> > |
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> > My Macbook Pro with light, normal usage lasts about three hours (OS X |
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> > lasts at least one hour more). |
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> > |
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> > m. |
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> |
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> Have you found any reason for this discrepancy? I'd suspect them to be |
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> on par with the right tuning. |
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> |
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Are you doing any kind of CPU frequency scaling? In the kernel (I use gentoo |
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sources) configuration enable |
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Power Management |
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- CPU frequency scaling |
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- performance (is selected as default) |
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- ondemand governor |
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- conservative |
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- ACPI Processor P-States driver |
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- Intel Enhanced SpeedStep |
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This enables frequency scaling... this works for my Core2 desktop so I |
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suspect it should work for the mac book too. |
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To select the actual cpu scaling governor to use, you can do the following |
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(as root) |
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echo ondemand > /sys/devices/system/cpu/cpu(n)/cpufreq/scaling_governor |
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where you need to this for all the cores... for my Core 2 desktop I have |
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cpu0 and cpu1. |
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You can select between ondemand, conservative and performance. Try both |
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ondemand and conservative... My guess is there will be little difference in |
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power consumption between the two and ondemand may be better for response |
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time sensitive loads (typical desktop usage). |
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I keep the above command in /etc/conf.d/local.start so that I get the CPU |
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freq scaling goodness on every boot :) |
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# /etc/conf.d/local.start |
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# This is a good place to load any misc programs |
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# on startup (use &>/dev/null to hide output) |
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gov=ondemand |
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echo "Switching to the '$gov' cpu frequency scaling governer." |
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echo $gov > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor |
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echo $gov > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor |
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_r |
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