2.7Ghz Processor not overclocked.

Discussion in 'Macintosh Computers' started by simie, Aug 23, 2005.

  1. simie macrumors 6502a

    simie

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    #1
    Somewhere on the forum, I remember a discussion taking place over the 2.7GHz Power PC's being over-clocked. I have found this article, that suggests otherwise.

    IBM actually designed the 970FX microprocessor to operate at speeds of up to 2.7GHz. Here is some proof.

    The 64-bitPowerPC 970FX microprocessor builds on the proven 64-bit IBM Power Architecture family and is suited to embedded applications including imaging and networking, and provides new levels of performance and power management for the embedded marketplace. Designed to run at frequencies up to 2.7 GHz, the PowerPC 970FX includes a 512KB L2 cache, provides native 64-bit and 32-bit application compatibility and uses a high bandwidth processor bus capable of delivering up to 7.1 GB/s to keep the processor core and the SIMD/Vector engine fed with data. The processor core can dispatch five instructions per cycle, and issue one instruction per cycle to each of its ten execution units, including two fixed point, two floating point, two load store, two vector and two system units. The L1 instruction cache holds 64 KB, the L1 data cache holds 32 KB, and each processor has its own dedicated 1MB L2 cache.

    This extract was taken from

    http://www-1.ibm.com/press/PressSer...lass&SESSIONKEY=any&WindowTitle=Press+Release

    Sorry if this as already been posted.
     
  2. Dont Hurt Me macrumors 603

    Dont Hurt Me

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  3. Sun Baked macrumors G5

    Sun Baked

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    May 19, 2002
    #3
    Because it was also tested to operate at 2.7GHz with water cooling in mind.

    Apple has a more elaborate specifications for cooling on their performance level chips, while the consumer and server chips need a cooler running chip.

    IBM is just delivering what Apple requested -- even if it is a 100W chip and running twice as hot as anything that would ever be put in a consumer machine and/or server.
     
  4. Mord macrumors G4

    Mord

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    #4
    to reduce noise, have you heard a 130w p4 pc at full load, it's like a jet engine, and apple does not want a jet engine, apple could fan cool it, but it would be too noisy, and they dont want another MDD G4.


    apple uses thier cpu's as rated by IBM/motorola to within about 40MHz (thats due to bus multiplers not working out, like the 1.42GHz MDD used a 1.4GHz chip and the 1.06GHz powerbook/ibook used a 1GHz rated cpu)

    these cpu's are produced on a much smaller scale to that of intel or AMD cpu's so IBM can afford to reduce voltage when it is not needed on lower speed chips compared to AMD or intel which just sets the voltage for the whole line and decides speed by statistical analysis of yield.

    my athlon at the moment has the exact same die size as the 970FX but runs at 1.4V (actually i have it running at 2.8GHz on 1.6V but i'm talking stock here) and is produced in the same plant as the G5 (i know athlons are produced in many plants but fishkill is one of them) and the G5 runs at 1.2V well below the K8, and it cant run stable over 1.3 volts and the 2GHz 105c rated part uses less power (39w max, not typical, max) than the athlon which is set at 1.4V accross the board and dissipates 67w max, IBM just tunes their cpu's to a greater degree than AMD and intel do.
     
  5. MRU macrumors demi-god

    MRU

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    #5
    But!!

    Can someone explain to me how the Xbox360 has managed to use 3 3ghz G5 chips and yet the powermac only goes upto 2.7

    How did ibm pull another 300mhz out of its ass? :confused:
     
  6. Sun Baked macrumors G5

    Sun Baked

    Joined:
    May 19, 2002
    #6
    Money and volume, IBM knows MS has the volume so they are willing to spend the money.

    For Apple to get IBM to bring the chips up to speed, they'd have to kick in those $100 million bills like AMD did for their chips.

    Apple's next chip in the line was the Power6-UL, IBM pulled it off the table completely and told Apple they were responsible for development from now on because the Power5-UL is a market failure.

    Basically, IBM was willing to move at the speed Apple was willing to pay for.

    The Intel move, completely eliminated the Motorola/IBM payola.

    Apple is an extremely high-profile loss-leader for IBM, but IBM had limits to the amount of funds they were willing to burn.

    Those leaps bringing the PPC up to x86 parity, were all marketing attempts to grab market share that quickly fizzled.
     
  7. Mord macrumors G4

    Mord

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    #7
    the xbox 360 cpu is not a G5, the buggest difference being it's lack of out of order execution, and it's not at all based on the power4 like the 970 is.
     
  8. Dont Hurt Me macrumors 603

    Dont Hurt Me

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    #8
    If i took a radiator and added it to my Powermac or Macmini or say Alienware everyone of them would be able to run faster and stable.
     
  9. Mord macrumors G4

    Mord

    Joined:
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    #9
    and? it's just better more efficient cooling, people said the same thing when they started useing heatsinks and the same thing when they started useing fans, and they will say the same thing when we start seeing phase change.
     

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