Vinay Devadas wrote: > Hi, > > ----- Original Message ----- > From: Mark Haywood <Mark.Haywood at Sun.COM> > Date: Tuesday, July 22, 2008 5:35 pm > Subject: Re: [tesla-dev] Question on PowerTop V 1.1 > To: Vinay Devadas <Vinay.Devadas at Sun.COM> > Cc: tesla-dev at opensolaris.org > > > >> Vinay Devadas wrote: >> >>> Hi, >>> >>> I ran powertop V 1.1 on a laptop with the following supported frequencies, >>> >>> 800:1200:1600:2000:2400:2401 >>> >>> PowerTop also lists 2401MHz as a P state (P0). Is this correct ? I >>> >> thought 2401MHz is the Turbo Mode frequency. Can someone please >> clarify this. Is there a way one can check if the processor supports >> turbo mode through the BIOS ? >> >>> >>> >> Turbo Mode is advertised as P0. So, yes this is correct. There is an >> outstanding RFE for PowerTop to calculate an average frequency while >> in >> Turbo Mode. I'm not sure how this is going to be presented. >> >> > > If Turbo Mode itself is advertised as P0, what does it mean to say "average > frequency" ? Is it not that, the processor only runs in Turbo Frequency > (2401Mhz in the example) for a while when it over clocks itself in P0(which > I thought was 2400MHz)? >
No. When it runs at P0, then the minimum frequency it will operate at is 2400MHz. But it is very likely to run faster than that and yes, I believe it may even run faster than 2401MHz. So, the "average frequency" as far as I know is the average speed while in P0. I believe that the APERF/MPERF registers will be used to determine the average frequency. But I'm not working on that, so maybe I should let someone else answer that. ;-) Mark > Thanks > -Vinay > > > >> As for BIOS settings for Turbo Mode, I think it depends on the BIOS as >> >> to whether or not there is a setting to enable/disable Turbo Mode. >> >> I think that you can read the ia32_misc_enable msr to find out whether >> >> or not it is enabled. >> >> Mark >> >> >>> Thanks, >>> Vinay >>> _______________________________________________ >>> tesla-dev mailing list >>> tesla-dev at opensolaris.org >>> http://mail.opensolaris.org/mailman/listinfo/tesla-dev >>> >>> >> _______________________________________________ >> tesla-dev mailing list >> tesla-dev at opensolaris.org >> http://mail.opensolaris.org/mailman/listinfo/tesla-dev >>
