From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arjan van de Ven Subject: Re: [Discuss] Speedstep on Celeron SU2300 - 20% more battery lifetime on Windows Date: Mon, 06 Sep 2010 16:28:10 -0700 Message-ID: <4C85790A.50005@linux.intel.com> References: <201009020152.37466.trenn@suse.de> <201009061035.03727.trenn@suse.de> <4C850D10.2050801@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: cpufreq-owner@vger.kernel.org To: Tiago Marques Cc: Thomas Renninger , discuss@lesswatts.org, linux-pm@lists.linux-foundation.org, cpufreq@vger.kernel.org, linux-acpi@vger.kernel.org List-Id: linux-acpi@vger.kernel.org On 9/6/2010 3:03 PM, Tiago Marques wrote: > On Mon, Sep 6, 2010 at 4:47 PM, Arjan van de Ven wrote: >> On 9/6/2010 1:35 AM, Thomas Renninger wrote: >>> Hi, >>> >>> I am adding lesswatts.org and linux-pm list. >>> I expect you found out why you do not get frequency/P- states and it >>> seem to be correct. On these lists, people can help you further >>> to find out Linux vs Windows battery drain differences. >>> >>> If you have the same backlight settings, I expect C-state or graphics >>> card must be the reason. There is nothing else than CPU or GPU >>> that drains so much energy for being the reason of >>> 20% more battery life time. >>> Which graphics card and driver do you use (for nvidia/ati, trying the >>> binary one for comparison, might show a big difference on a recent >>> card)? >>> Which C-state driver do you use (there is an acpi and intel_idle one >>> with latest kernels): >>> cat /sys/devices/system/cpu/cpuidle/current_driver >>> I hope to be able to provide a c-state tool soon, for now you have to >>> go through: >>> cat /sys/devices/system/cpu/cpu*/cpuidle/state* >>> to check which and how often/efficient C-states are used. >> powertop will tell you exactly this >> > Thank you. Please see my previous e-mail. C0, C1 and C4. Do you know > of any way to force the intermediate ones for debugging? intel_idle driver is the only way that's reasonable in amount of work. for anything else you depend on the grace of the bios.