Intel speedstep in windows

Discussion in 'Windows, Linux & Others on the Mac' started by warhead1, Mar 1, 2008.

  1. warhead1 macrumors newbie

    Mar 1, 2008
    I've just bit the bullet and purchased my first mac, but for now I mainly need to use windows.

    Now Apple claims upto 5hrs with the new Penryn MBPs, but in windows, the estimated battery life was 2hrs and 40mins. The CPU was running at 800Mhz while on battery in OSX, but in windows, it's 1.6ghz. Windows by default usually only supports 2 speed stepping profiles (reduced or full speed), but with 3rd party programs I've been able to tweak it much more with my other PC laptops.

    I installed Notebook Hardware Control (NHC) to try and adjust the CPU voltages and speed stepping, but all the settings are locked out, implying that the system doesn't support speedstep technology, in this case I believe it's got something to do with EFI and Bios emulation not working correctly (AHCI is detected as being disabled in NHC). Or it could be that the penryn CPUs are so new, no applications out there can do it yet.

    Does anyone know if there's a way I can set up proper speed stepping in Windows via bootcamp?

  2. Kyttlin macrumors newbie

    Jan 23, 2008
    I just recently purchased a MBP so I haven't tried Windows on the Mac much yet.

    With that in mind, another manual CPU control program that allows you to adjust the voltage is RMClock. I haven't tried it yet... last time I used this program was on my old laptop, which was a PC.
  3. warhead1 thread starter macrumors newbie

    Mar 1, 2008
    Yep I just found that out and gave the new 2.35 version a try. Apparently Penryn support is still preliminary and limited, but it did let me adjust CPU multiplier and throttling.

    But I think something is still glitched with it in that the default 8x multiplier when on battery has a VID of 0.95v, the VID of the 6x multiplier is actually higher!

    Other VIDs are in the 1.1v range, which still seems a bit high for the penryn.

    Even after mucking around with the throttling and bringing the CPU down to 300Mhz, the battery life never exceeded 3hrs estimate on a 96% charge.

    Screen brightness on level 3 and keyboard lighting was off, wifi is on.

    How on earth did Apple come up with the 5hr figure, and I've even read that that figure is WITH wifi enabled.

    What can be so different between OSX power management and Windows? I mean there's only a limited number of hardware components that you can control the power of.
  4. webgoat macrumors 6502a


    Sep 20, 2007
    Austin, TX
    i get close to 4 hours with leopard on around half brightness and moderate use whereas in vista ultimate i'll get around 2 hours doing the same
  5. Sptz macrumors regular

    Aug 8, 2007
    I got the exact same problem, I guess it's normal... it looks like Windows uses a lot more power than OSX, another thing I have a problem with is that I can't get the screen to shut down on a certain period of time like on OSX, instead it just stays always on, and occasionally when it does, I have to press any of the brightness keyboard buttons to be able so "see" again.... I wonder if it has anything to do with the powermizer from nv drivers... it's a bit confusing..

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