So, why have two GPU's in the macbook pro?

Posted:
in Current Mac Hardware edited January 2014
Hi,



In regards to the new Macbook Pro's, what's the reason for having the two GPUs in them? They can't actually run in SLI can they? So one is on while the other is off.



Wouldn't it have been cheaper just to put the 9600 GT in there on its own?



Am I being a wee bit naive here or does what I ask make sense?

Comments

  • Reply 1 of 12
    bbwibbwi Posts: 812member
    You might be correct but we'll never know. The idea behind the two chips is that while you're on battery you'll get good graphics but while you're plugged in you'll get great graphics and even greater overall performance with OpenCL.
  • Reply 2 of 12
    Quote:
    Originally Posted by RabidRabbit View Post


    Hi,



    In regards to the new Macbook Pro's, what's the reason for having the two GPUs in them? They can't actually run in SLI can they? So one is on while the other is off.



    Wouldn't it have been cheaper just to put the 9600 GT in there on its own?



    Am I being a wee bit naive here or does what I ask make sense?



    There is only one GPU in the Macbook Pro, the 9600M GT. The 9400M is an IGP, an integrated graphics processor built into the Nvidia chipset. Theoretically, the reason is to save power, by allowing you to turn off the 9600M GT when it is not needed.
  • Reply 3 of 12
    Ah ok.



    However, wouldn't it still be easier just to have one and not bother with the other? Surely it still makes the manufacturing process more expensive?
  • Reply 4 of 12
    nikon133nikon133 Posts: 2,600member
    Quote:
    Originally Posted by RabidRabbit View Post


    Ah ok.



    However, wouldn't it still be easier just to have one and not bother with the other? Surely it still makes the manufacturing process more expensive?



    Well... they could get rid of additional 9600 GT, but that would cripple 3D performance. I'm not sure if there is chipset version without integrated 9400M.



    If I understood correctly how whole thing works, system will use 9400M for common work - OS GUI, 2D apps... 9400M is more than good enough for that and should be significantly less power hungry, so if you are on battery power, you should be happy.



    However, when you run 3D app (game, or software that benefits from extra GPU power) system should seamlessly switch to 9600GT, giving you extra muscle but with the price of more heat, more power consumption and, for mobile users, shorter battery life.



    Now... it would be great if there is graphics chip, say 9600GT-M, that can scale down (when 3D not required) and have consumption/heat of integrated graphics, but it seems not to be the case... for now. I believe that AMD is - or at least was, recently - using same dual-chip solution for their notebook platforms.
  • Reply 5 of 12
    Quote:
    Originally Posted by nikon133 View Post


    Well... they could get rid of additional 9600 GT, but that would cripple 3D performance. I'm not sure if there is chipset version without integrated 9400M.



    If I understood correctly how whole thing works, system will use 9400M for common work - OS GUI, 2D apps... 9400M is more than good enough for that and should be significantly less power hungry, so if you are on battery power, you should be happy.



    However, when you run 3D app (game, or software that benefits from extra GPU power) system should seamlessly switch to 9600GT, giving you extra muscle but with the price of more heat, more power consumption and, for mobile users, shorter battery life.



    Now... it would be great if there is graphics chip, say 9600GT-M, that can scale down (when 3D not required) and have consumption/heat of integrated graphics, but it seems not to be the case... for now. I believe that AMD is - or at least was, recently - using same dual-chip solution for their notebook platforms.



    Ah, I meant keep the 9600 aspect and just do away with the 9400M.
  • Reply 6 of 12
    From what I understand, they can run in SLI in Windows, but Apple hasn't enabled that feature.
  • Reply 7 of 12
    irelandireland Posts: 17,535member
    Real reason? Snow Leopard. Duh!
  • Reply 8 of 12
    Quote:
    Originally Posted by Ireland View Post


    Real reason? Snow Leopard. Duh!



    Huh? What do you mean?
  • Reply 9 of 12
    Quote:
    Originally Posted by nikon133 View Post


    However, when you run 3D app (game, or software that benefits from extra GPU power) system should seamlessly switch to 9600GT, giving you extra muscle but with the price of more heat, more power consumption and, for mobile users, shorter battery life.



    Now... it would be great if there is graphics chip, say 9600GT-M, that can scale down (when 3D not required) and have consumption/heat of integrated graphics, but it seems not to be the case... for now. I believe that AMD is - or at least was, recently - using same dual-chip solution for their notebook platforms.



    It's not seamless, you have to log out and log back in to make the switch. And graphics chips already "scale back" by reducing their core clock at idle. That's not as effective as completely shutting down the GPU, though.



    Quote:
    Originally Posted by RabidRabbit View Post


    Ah, I meant keep the 9600 aspect and just do away with the 9400M.



    Nvidia doesn't make a mobile chipset without an IGP. Apple could have stuck with an Intel chipset for the MBP, but that wouldn't have saved them anything.
  • Reply 10 of 12
    Quote:
    Originally Posted by RabidRabbit View Post


    Ah, I meant keep the 9600 aspect and just do away with the 9400M.



    To save power, to have the 9400M there being used most of the time during normal everday web surfing etc.



    And yeah, the motherboard is more or less the same from the MacBook, so to use the 9400M etc in the MacBook Pro is more efficient to manufacture?
  • Reply 11 of 12
    Quote:
    Originally Posted by bbwi View Post


    You might be correct but we'll never know. The idea behind the two chips is that while you're on battery you'll get good graphics but while you're plugged in you'll get great graphics and even greater overall performance with OpenCL.



    Yes, ideally. I think that's what Ireland is referring to regarding Snow Leopard.



    Right now the MacBook Pro is an either-or, either you use 9400M or log out and log in using 9600. True high performance hybrid SLI etc for GP GPU (OpenCL) and Graphics ... maybe sometime next year.



    Given the direction their pushing, it would be very interesting when the drivers and software and OS X Snow Leopard all come together. You've got your two (or four?) Intel CPU cores, the 9400 GPU and the 9600 GPU all working together... ebony and ivory... in pefect harmony.......
  • Reply 12 of 12
    flounderflounder Posts: 2,674member
    Quote:
    Originally Posted by RabidRabbit View Post


    Ah ok.



    However, wouldn't it still be easier just to have one and not bother with the other? Surely it still makes the manufacturing process more expensive?



    Actually, it probably makes the manufacturing process less expensive because they are using the same chipset as the macbook.
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