Messages in this thread | | | Date | Fri, 17 Aug 2012 20:50:34 +0100 | From | Matthew Garrett <> | Subject | Re: [discussion]sched: a rough proposal to enable power saving in scheduler |
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On Fri, Aug 17, 2012 at 01:45:09PM -0600, Chris Friesen wrote: > On 08/17/2012 12:47 PM, Matthew Garrett wrote:
> The datasheet for the Xeon E5 (my variant at least) says it doesn't > do C7 so never powers down the LLC. However, as you said earlier > once you can put the socket into C6 which saves about 30W compared > to C1E. > > So as far as I can see with this CPU at least you would benefit from > shutting down a whole socket when possible.
Having any active cores on the system prevents all packages from going into PC6 or deeper. What I'm not clear on is whether less deep package C states are also blocked.
-- Matthew Garrett | mjg59@srcf.ucam.org
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