All of lore.kernel.org
 help / color / mirror / Atom feed
From: Robert Hancock <hancockr@shaw.ca>
To: Tomasz Chmielewski <mangoo@wpkg.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: Re: PROBLEM: Celeron Core
Date: Mon, 21 Jan 2008 17:59:46 -0600	[thread overview]
Message-ID: <479531F2.3010607@shaw.ca> (raw)
In-Reply-To: <fa.tHyDHqRNYFvp4N4SR4JtJRuqh0k@ifi.uio.no>

Tomasz Chmielewski wrote:
>>> Clock throttling is not likely to save your battery, unless you have 
>>> tasks that are running at 100% CPU for an unlimited time or 
>>> something, and you force your CPU to throttle. Normally most people 
>>> have tasks that run and then the CPU idles - loading an email, 
>>> displaying a web page, etc. Clock throttling will just make these 
>>> tasks utilize the CPU for a longer time proportional to the amount 
>>> clock throttling and therefore negate any gains in battery usage.
> 
> Aren't you forgetting about CPUfreq governors? Which mean: use the 
> maximum CPU frequency when the system is busy, throttle down (or lower 
> voltage) when the system is idle.
> 
> So yes, throttling will save the battery.

We are talking about throttling (i.e. P4 clockmod) not CPU frequency 
scaling. Clock modulation does not reduce the clock speed, it just 
basically forces the CPU to halt on a certain duty cycle. If the CPU is 
already idle this has no effect and won't save any power.

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/


       reply	other threads:[~2008-01-22  0:00 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <fa.tHyDHqRNYFvp4N4SR4JtJRuqh0k@ifi.uio.no>
2008-01-21 23:59 ` Robert Hancock [this message]
2008-01-20 22:06 PROBLEM: Celeron Core Tomasz Chmielewski
2008-01-20 22:26 ` Rafael J. Wysocki
2008-01-21 10:11 ` Matthew Garrett
     [not found] <fa.2Y+LplM9PCtpiAXzv/aJ3Pcnv4Y@ifi.uio.no>
     [not found] ` <fa.OpXJDCw416yeXEvt0cwrupi/qS0@ifi.uio.no>
     [not found]   ` <fa.sj34KNXkf9z/ZO3fVJ+CYcgcuCs@ifi.uio.no>
     [not found]     ` <fa.qpK4b5H7lkLeIaPtbJKzKV46yFY@ifi.uio.no>
     [not found]       ` <fa.WeBRuL3UPPVPESVzfopvVyNcAw4@ifi.uio.no>
     [not found]         ` <fa.LZLUxfR64dAZFPtin9JNet7ieiY@ifi.uio.no>
2008-01-20 18:24           ` Robert Hancock
2008-01-20 19:14             ` Matt Mackall
2008-01-20 19:24               ` Robert Hancock
2008-01-20 21:31                 ` Rafael J. Wysocki
2008-01-21  7:48               ` Daniel Barkalow
2008-01-20 19:16             ` Andi Kleen
  -- strict thread matches above, loose matches on Subject: below --
2008-01-18 19:06 Chodorenko Michail
2008-01-18 21:11 ` Andi Kleen
2008-01-19  0:27   ` Matt Mackall
2008-01-19  1:15     ` Andi Kleen
2008-01-19  4:10       ` Matt Mackall
2008-01-19  4:27         ` Andi Kleen
2008-01-19  4:40           ` Matt Mackall
2008-01-19  4:54             ` Andi Kleen
2008-01-20  4:35               ` David Newall
2008-01-20  5:13                 ` Andi Kleen
2008-01-20  5:23                   ` David Newall
2008-01-20  5:42                     ` Andi Kleen
2008-01-20 20:53                     ` Lennart Sorensen
2008-01-20 11:18           ` Geert Uytterhoeven

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=479531F2.3010607@shaw.ca \
    --to=hancockr@shaw.ca \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mangoo@wpkg.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.