CrazyLexx Posted July 30, 2007 Share Posted July 30, 2007 Hi there, I remember reading somewhere that Apple underclocks the ATI Mobility x1600 GPU when running MacOS on a MacBook Pro. I'm currently using Vista on MBP C2D and get get the powersaving features of the ATI card to work at all, causing my notebook to run at full speed all the time. Is it possible to somehow manually underclock the GPU under Vista? If so, to what level does Apple underclock the GPU under MacOS? Thanks, TOM Link to comment Share on other sites More sharing options...
EFI Posted July 31, 2007 Share Posted July 31, 2007 Apple severlely underclocked the X1600 only on the first Core Duo Macbook Pro's..the first revision. The second rev. Core 2 Duo MBP's...had their X1600 back up to almost normal speeds thanks to a better air exhaust design on the laptop, as well as better logic boards, and they were underclocked by only 5%...compared to the near 30% on the first CD MBPs'. The current and latest Macbook Pro's, have the 8600M GT's, which have a feature called dynamic clocking. Essentially the GPU slows down significantly when it's not doing anything, thus saving power and heat, and then powers up to full speed when under pressure (ie. gaming). The same is the result with the processor, with Intel's powermizer technology on the latest MBP's, the processor actually shuts off 1 of the cores, and powers down the other core to a minimum when not doing anything..again, saving power. This can be seen when you go to My comptuer > properties under Windows XP, where the processor speed and the current speed will be vastly different when the laptop is not doing anything. Load up a game, and check the same thing, and you will see that BOTH the processors are working at the full or close to full power, thus yielding the 2.4Ghz range. The previous Core 2 Duo Macbook Pro's, which is the one you have, I dont think has the powermizer technology built in, and I know for sure that the X1600's dont have dynamic clocking...in which case, unless you manually lower the clock/memory speeds using software like ATItool, there is really no other option. - hope it helps. Link to comment Share on other sites More sharing options...
macprodan Posted August 15, 2007 Share Posted August 15, 2007 The X1600 in the Rev 2 MBP does use Dynamic Clocking, as do nearly all mobile GPU`s.. Dont know why in Vista it runs full speed all the time.!! have you used diff drivers from the various bootcamp versions.? Link to comment Share on other sites More sharing options...
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