On Sun, Jul 22, 2007 at 09:19:17PM -0700, Arjan van de Ven wrote: > let me give you a real world example then, and the numbers I'm using are > ballpark the same as you'll find in a (mobile) core 2 duo datasheet, I > just rounded them a little so that the math works out nice. > > power at full speed: 34W > power at half speed: 24W > power at idle: 1W I have usually seen different numbers, for example: http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/30430.pdf Although this paper speaks about thermal design power instead of power consumption, i suppose that it should be roughly equal. For example Athlon 64 3700 (ADA3700AEP5AR): 2.4 GHz, 1.5 V -> 89 W 2.2 GHz, 1.4 V -> 72 W 2.0 GHz, 1.3 V -> 53 W 1.8 GHz, 1.2 V -> 39 W 1.0 GHz, 1.1 V -> 22 W Even my measurement on PC (Athlon X2, VIA K8T890) of complete PC power consumption shows that it is more efficient to be busy for 2 time units on 1 GHz than be busy for 1 time unit and be idle for 1 time unit on 2 GHz. 1 GHz: both cores idle: 48 W one core busy: 57 W two cores busy: 66 W 2 GHz: both cores idle: 54 W one core busy: 78 W two cores busy: 95 W -- Elen sila lumenn' omentielvo Ondrej 'SanTiago' Zajicek (email: santiago@xxxxxxxxxxxxx, jabber: santiago@xxxxxxxxxxxxx) OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net) "To err is human -- to blame it on a computer is even more so." _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
