lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Tue, 9 Oct 2007 14:28:57 -0400
From:	lsorense@...lub.uwaterloo.ca (Lennart Sorensen)
To:	"Kok, Auke" <auke-jan.h.kok@...el.com>
Cc:	Pavel Machek <pavel@....cz>,
	Arjan van de Ven <arjan@...radead.org>,
	kernel list <linux-kernel@...r.kernel.org>
Subject: Re: gigabit ethernet power consumption

On Mon, Oct 08, 2007 at 03:31:51PM -0700, Kok, Auke wrote:
> you most certainly want to do this in userspace I think.
> 
> One of the biggest problems is that link negotiation can take a significant amount
> of time, well over several seconds (1 to 3 seconds typical) with gigabit, and
> having your ethernet connection go offline for 3 seconds may not be the desired
> effect for when you want to get more bandwidth in the first place.
> 
> However, when a laptop is in battery mode, switching down from gigabit to 100mbit
> makes a lot more sense, so this is something I would recommend. This can be as
> easy as changing the advertisement mask of the interface and renegotiating the
> link. Userspace could handle that very easily.

Now if you were trying to transfer a lot of data to the laptop, would it
be more power efficient to do it at gigabit speeds so you can finish
sooner and shut down the machine entirely, or to slow to 100mbit and
take longer to do it, and hence spend more time powering the cpu and
ram?

--
Len Sorensen
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ