On Fri, Aug 03, 2012 at 09:22:12AM +0800, Sepherosa Ziehau wrote: > On Fri, Aug 3, 2012 at 2:00 AM, Sven Gaerner <sgaer...@gmx.net> wrote: > > On Tue, Jul 31, 2012 at 09:27:15AM +0800, Sepherosa Ziehau wrote: > >> On Tue, Jul 31, 2012 at 5:01 AM, Sven Gaerner <sgaer...@gmx.net> wrote: > >> [...] > >> > >> Hmm, maybe i8254 is not working at all. Could you post following > >> information: > >> - bootverbose dmesg w/ hw.i8254.intr_disable="0" in /boot/loader.conf > >> - sysctl kern.cputimer > >> - sysctl hw.acpi > > > > Attached the requested details. > > Grrr, only C1 is detected. If the CPU does support C3, there could be > some settings in BIOS? > > Best Regards, > sephe > > -- > Tomorrow Will Never Die
The BIOS settings are very limited. I did not find anything that looks like configuring the C-states. You can just enable/disable the HPET timer, the ACPI wake states (S1 or S3) and other settings that are not related to ACPI/frequency scaling like configuring the USB ports. It looks like FreeBSD also doesn't detect the settings well: http://lists.freebsd.org/pipermail/freebsd-acpi/2011-August/007264.html I guess there is no chance to get C3 states working. I looked into the manual [1] and on page 28ff the table lists the expected power consumption when the system is in various states. I did not see any C3 state there, only C1. So I guess I have to use this board with the limitation or think about changing to a board that supports frequency scaling. Thanks for your support. Regards, Sven [1] http://downloadmirror.intel.com/19123/eng/D525MW_D525MWV_TechProdSpec.pdf