From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gunter Ohrner Subject: Re: cpufreq: powernow-k8 frequency transitions question Date: Sat, 07 Jan 2006 15:28:12 +0100 Message-ID: References: <84EA05E2CA77634C82730353CBE3A84303D430BD@SAUSEXMB1.amd.com> <20060103162946.GF13887@poupinou.org> <43BB29FF.2000401@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: 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="iso-8859-1" To: cpufreq@lists.linux.org.uk Nebojsa Trpkovic wrote: > The most usefull powersaving is achieved by lowering the voltage and not = > the further lowering of frequency. Yes, but lower clock speeds usually allow for lower voltages, so that's what you gain by lowering the core frequency. > minimum stable voltage just to be 110% sure it will work stable: > Winchester runs with 1.0GHz @1.0V and 1.8GHz @1.275V I'm currently running my Winchester 3000+ at 1,0GHZ@1,0V and 1,8GHz@1,15V only, and it's rock solid for me so far - it survived hours of 100% cpu load during normal operation and using cpuburn's burnK7, either locked at on of the frequencies or in dynamic mode using the ondemand governor. > So, I've modified powernow-k8.c to lower the voltages read from BIOS for = > every p-state. Changing the vlaues returned by the BIOS by a function is a really interesting approach, especially if there's not much point in providing additional P-states, which is my current impression. At the moment I have ACPI table queries turned off in powernow-k8 and supply a hand craftes PSB table, but obviously that's not the most flexible solution. Mh, two VID and FID mapping function's which initially are identity functions but with some sysfs-tuneable parameters sounds interesting to me... :-) I guess I should try that. Greetings and thanks for that idea, Gunter --=20 The question seldom addressed is *where* Medusa had snakes. Underarm=20 hair is an even more embarassing problem when it keeps biting the top=20 of the deodorant bottle. -- (Terry Pratchett, Soul Music) *** PGP-Verschl=FCsselung bei eMails erw=FCnscht :-) *** PGP: 0x1128F25F ***