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. > 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. 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
