Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754813AbXJLCI4 (ORCPT ); Thu, 11 Oct 2007 22:08:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752754AbXJLCIt (ORCPT ); Thu, 11 Oct 2007 22:08:49 -0400 Received: from moutng.kundenserver.de ([212.227.126.188]:56478 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751641AbXJLCIs (ORCPT ); Thu, 11 Oct 2007 22:08:48 -0400 From: Bodo Eggert <7eggert@gmx.de> Subject: Re: gigabit ethernet power consumption To: Kok@vger.kernel.org, Auke , prasad@linux.vnet.ibm.com, Lennart Sorensen , Pavel Machek , Arjan van de Ven , kernel list Reply-To: 7eggert@gmx.de Date: Fri, 12 Oct 2007 04:08:29 +0200 References: <9c8XH-7gs-13@gated-at.bofh.it> <9c9qN-7Rn-19@gated-at.bofh.it> <9cs0n-3Dc-9@gated-at.bofh.it> <9csjH-43E-33@gated-at.bofh.it> <9d4yC-5hT-7@gated-at.bofh.it> <9d7ZJ-2mI-11@gated-at.bofh.it> User-Agent: KNode/0.7.2 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8Bit Message-Id: X-be10.7eggert.dyndns.org-MailScanner-Information: See www.mailscanner.info for information X-be10.7eggert.dyndns.org-MailScanner: Found to be clean X-be10.7eggert.dyndns.org-MailScanner-From: 7eggert@gmx.de X-Provags-ID: V01U2FsdGVkX1/GgxRsj8dqydpqPMW0giQcmMeSaJplWOun9qW EHaZaVmKKf1cHrbfatz6tDl+4x5bX7CakchVmchYhuERm5WSkU 74YGQOpmv+GtLi+SkhbVw== Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1491 Lines: 27 Kok, Auke wrote: > K.Prasad wrote: >> Without the side-effect of experiencing a link-flap when switching to a >> lower-speed (with its toll in terms of down-time for auto-negotiation, >> STP, etc), the Interrupt Moderation Algorithm dynamically adjusts the >> number of interrupts based on traffic - and presumably consume less >> power. For an "Optimise for Power" kind of profile - the driver can be >> loaded with a higher throttle rate during boot-time. > > We're changing this to be run-time adjustable in newer drivers. > > However, the power consumed by your nic staying in gigabit mode is much > greater in the long run then what you can save by trying to scrounge for > milliwatts reducing interrupts generated by the nic. By default it already > moderates them somewhat. Practically this feature is really not useful for > powersaving, it just won't add up to actual benefits in a real life situtation > I think. Just a thought: How much power does a non-connected NIC consume, and can you save power by forcing 10 MBit until a link is detected (doubling negotiation time)? -- Top 100 things you don't want the sysadmin to say: 22. hey, what does mkfs do? Fri?, Spammer: 9nnbse9@lgrrp.7eggert.dyndns.org - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/