Heres a question for you PB experts

Discussion in 'Buying Tips, Advice and Discussion (archive)' started by CaptainCaveMann, Dec 18, 2004.

  1. CaptainCaveMann macrumors 68000


    Oct 5, 2004
    Is the 1.5 processor in the current PB really an overclocked version of the very same processor in the lower model 1.33 PB? Or is it a different processor altogether? Also in regards to the ibooks i have the very same question in fact are all the g4 chips in apples line of notebooks the same processors but some are just overclocked? The reason i ask is because ive heard that overclocking causes excess heat and reliability issues but that has been said for PC's and it may be different for Mac's i dont know :confused: Maybe thats why the PB tends to run hotter than the ibook? Any input?
  2. crazzyeddie macrumors 68030


    Dec 7, 2002
    Florida, USA
    Reliability issues are not a concern. Almost all chip manufacturers market chips at lower rated speeds because of quality issues in production. In reality, a certain number of those chips are 100% stable when overclocked. Apple would not be selling Powerbooks with dangerously overclocked processors.
  3. Jigglelicious macrumors 6502


    Apr 25, 2004
    The problem here is that you are misusing the word 'overclocked'. An overclocked processor means that someone is running a processor at a speed higher than what it is officially rated for. For example, running a processor rated at 1ghz @ 1.2ghz.

    However, you first need to understand how processors are manufactured and then rated. Believe it or not, every single G4 chip that Motorola sells comes from the exact same silicon wafers (barring different CPU revisions). One a processor is stamped out of that wafer, it is rigorously tested to determine is quality. Even though 20 CPU's might come from the same wafer, that doesn't mean they are all of the same quality. Some might only safely reach 1ghz. Some might go all the way up to 1.6ghz, or even higher. Some might not go past 500mhz, and have to be scrapped. Once a 'safe' range is decided for a processor, it is given a rating. All that rating means is that it is guaranteed to run at that rated speed.

    Of course, just because its rated for one speed, doesn't mean it can't go higher. If a company has extremely good CPU yields, they might end up sticking higher rated CPU's into slower machinges and "underclocking" them. That is basically how I was able to push a 800mhz G4 to 1.4GHz with no issues and no excess heat generated.

    In response to your question about the G4's in the Powerbook and iBook - yes, they did come from the same silicon wafers. One is rated at 1.5ghz while another is rated for 1.33ghz. They are identically the same exact chip, but one is just able to run at a higher speed more reliably. There is no 'overclocking' taking place here. Apple is simply following the speed ratings given to them by Motorola/IBM.

    I hope that clears things up.
  4. CaptainCaveMann thread starter macrumors 68000


    Oct 5, 2004
    Wow i just learned a lot i didnt know any of that... pretty cool :D
  5. maya macrumors 68040


    Oct 7, 2004
    somewhere between here and there.
    Interesting I will look into over clocking my 1.2Ghz G4 in the next 6 months bring it up to 2GHz if possible. :cool:

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