From mboxrd@z Thu Jan 1 00:00:00 1970 From: Len Brown Subject: Re: do Pentium4 & PentiumM consume about the same at their lowest possible freq? Date: Fri, 3 Aug 2007 14:16:58 -0400 Message-ID: <200708031416.58746.lenb@kernel.org> References: <46B35E55.6080705@unica.it> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <46B35E55.6080705@unica.it> Content-Disposition: inline List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: cpufreq-bounces@lists.linux.org.uk Errors-To: cpufreq-bounces+glkc-cpufreq=m.gmane.org+glkc-cpufreq=m.gmane.org@lists.linux.org.uk Content-Type: text/plain; charset="us-ascii" To: cpufreq@lists.linux.org.uk On Friday 03 August 2007 12:56, Roberto De Leo wrote: > Hi all, > I am not sure this is the right place where posing my question, if not > please suggest me a better one! > > I come to the question. > I happily used the speedstep kernel module with my centrino laptop and > it really made a difference in terms of battery duration (actually now I > have a celeron-m based laptop and the difference does not seem so > evident, but I still have little statistic on it). > Now I need to replace my main home 'desktop' PC and I am tempted to buy > a PentiumM-based minit-itx MB (e.g. the AOpen i945GTt-VFA) in order to > decrease the power bill (my PC is on 24/7), but since mini-itx MBs are > quite expensive I'd prefer first to know the following: can the "Intel > Pentium 4 clock modulation" kernel module (or maybe the "AMD > Opteron/Athlon64 PowerNow!" one) bring the corresponding CPUs to consume > as little as the "Intel Enhanced SpeedStep" does for a centrino? This > info is quite important but I could not find it anywhere! In general, no -- you are better off with a mobile-optimized processor. indeed, under many conditions, using pentium 4 clock modulation will actually increase energy use, rather than decrease it. -Len