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On Tue, Apr 27, 2010 at 10:21 AM, Mark Knecht <markknecht@×××××.com> wrote: |
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> Computers are a big portion of the bill around here and learning how |
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> to reduce power is high on my priorities for the next few months. I'm |
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> not sure how to handle a multi-use box like this. It's an 8-thread i7 |
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> processor. I was wondering about powering off certain core when the |
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> machine isn't doing much. Does Intel hardware do that? I need to |
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> determine how much power is in the processor, the chipset, memory, the |
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> disk drives. The machine is 3-drive RAID1 using data center drives. |
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> The WD Green drives just didn't work for RAID. I'm sure 3 drives is |
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> adding to my power consumption, but maybe they can be spun down more |
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> often. Myth recordings are currently stored on an external USB drive, |
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> so that's more power. |
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|
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Supposedly enabled and idle cores use even less power than disabled |
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cores because of the way the i7 handles C6 state. Intel claims power |
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usage in this state is approximately zero (not even any leakage). |
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|
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Enable C1E and EIST in your BIOS (they are powersaving options), |
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enable CPU frequency scaling in your Kernel and use ondemand governor |
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(As you would on a laptop). Disable unused network interfaces or SATA |
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controllers etc. in BIOS. |
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|
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NVidia cards using the proprietary drivers have powersaving and |
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underclocking options (enable the option "Coolbits" in your xorg.conf |
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and then use nvidia-settings to see these extra options) |
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I don't know if PSUs consume more power than necessary. For example if |
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you have a 650W power supply but could have gotten by with 380W, could |
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you save energy by using the smaller one? I'm not an electrical |
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engineer. :) |
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My new system has Samsung drives that seem to have a pretty aggressive |
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spindown time (at least compared to my old ones, which never |
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spundown). I was concerned about this in my RAID5 but what I have |
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really learned was how often my disks are idle. The spindown isn't so |
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aggressive that it happens while I'm actively using the system. |
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I am curious if enabling laptop-mode would have any positive effect on |
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a desktop that has these CPU & HDD power saving features? Or perhaps |
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disabling swap entirely and putting temp directories in /dev/shm. |
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Basically the same kind of techniques people having been using on |
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laptops for years to reduce disk activity and power consumption. It's |
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an experiment for a rainy day :) |
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