On Thu, Sep 2, 2010 at 12:52 AM, Thomas Renninger <trenn@xxxxxxx> wrote: > On Thursday 02 September 2010 01:17:14 Tiago Marques wrote: >> Hi Thomas. Thanks for the message. >> >> On Wed, Sep 1, 2010 at 11:40 PM, Thomas Renninger <trenn@xxxxxxx> wrote: >> > On Sunday 29 August 2010 06:54:44 Tiago Marques wrote: >> >> Hi, >> >> I'm having a problem with this processor not having frequency steps >> >> and apparently only voltage steps. I find it very strange but that's >> >> what Intel's documentation suggests. I can't load acpi-cpufreq because >> >> it doesn't find any device and battery life in linux is suffering >> >> around 20% less due to this. >> > Where do you have the 20% info from, I doubt you verified it? >> >> Yes. Since it seems no one can't return Windows licenses for refunds >> anymore, I have went ahead and booted windows on it, without any >> driver installed and just configured it to have frequency scaling >> working, which in this case is only voltage scaling. >> I measured almost 6 hours of battery life and the processor & chipset >> frequently had the fan stop when idling. >> >> In linux, in the same conditions, I got less than 4 hours and the fan >> never stops. I configured a PCI-express power saving feature on the >> kernel and it seems to have dropped noise a bit. Battery life is still >> not great and the fan still never stops. I'm trying to find something >> with which I can measure the actual power going through the AC adapter >> but for now battery life tests is pretty much all I can do. > There is current battery power drain somehwere in > /proc/acpi/battery/*/* > It normally updates not that often, but may be better and accurate enough if you > take several values, than waiting for the battery got drained. Thanks, I'll look into that for kernel tuning. I just can't use to compare with windows because I don't think I have similar information there. > >> The 20% figure is obviously optimistic since I'm accounting a positive >> effect from the PCI-Express power saving feature to not quote 33% >> less. > Yep, this could be the graphics card as well. > What kind of graphics card has it and which driver are you using? > >> >> I have confirmed that the CPU supports >> >> Speedstep, just this very strange variation. >> > You are not the only one: >> > https://bugzilla.kernel.org/show_bug.cgi?id=16072 >> > [HP Pavilion dm1-1110ev] Cpufreq doesn't work at all ( Intel Celeron U2300 ) >> > or the last comments (or search for U2300) here: >> > http://software.intel.com/en-us/articles/enhanced-intel-speedstepr-technology-and-demand-based-switching-on-linux/ >> > >> >> Can I somehow help with this to get it fixed? Who are the current maintainers? >> > Not exporting cpu frequencies seem to be intended for this cpu for whatever reasons. >> >> It doesn't have more than one. I checked in windows and I also can't >> change frequency, despite reports from a person on the contrary: >> >> http://scottiestech.info/2010/02/05/how-to-increase-your-laptops-battery-life-a-lot-with-crystalcpuid/ >> >> I have confirmed that the GM45 chipset doesn't support frequency >> scaling of the FSB on Intel's datasheet, so the speed he reports of >> 98MHz is a bug. I found similar frequencies upon use. Since I >> performed my tests with LCD brightness in full, that would account for >> the one hour difference on the best result, while the less than four >> hours he also reports may be due to speedstep not working before he >> messed with configurations. >> >> I tried the same program and the CPU is locked at 6x, although the >> voltage isn't, it's somewhere from 0.925 to 1.075v if I recall >> correctly. >> >> > If you have efficient C-states, frequency states are not that important. >> >> I know. But what about voltage? Intel's datasheet clearly states this >> processor supports two voltage states, I guess for the purpose of >> relaxing clock binning requirements for these CPUs. I'm thinking it >> does scale when in windows. >> The Pentium SU4100 has similar problems but he allows one p-state, >> from 1300MHz to 1200MHz. >> I can't seem to find the lowest multiplier available on these >> platforms, CrystalCPUID lists mine as 6x, hence 1200MHz. I thought >> Core 2's could idle at something like 800MHz and I find it strange >> that this one can't also. > Interesting. Possibly you have luck finding a document from Intel about > this CPU describing this a bit. I'd be interested in the outcome, but don't > have to time to dig for it. http://www.intel.com/design/mobile/datashts/321111.pdf Please have a look at this document, page 30, note 10, at the top of the page. Do you have any experience with SU processors? I have no idea of idle clock of the Core 2 SU CPUs, perhaps it is also 1200MHz, hence the limitation on idle clock? Could be the lowest multiplier available. Best regards > > Thomas > -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
