MBA 2012: maximum shared memory with HD4000?

Discussion in 'MacBook Air' started by Dwee8le, Jun 14, 2012.

  1. Dwee8le macrumors member

    Joined:
    Aug 1, 2010
    Location:
    Amsterdam, Holland
    #1
    Hello,

    I am wondering how much RAM is used (or could be used) by the HD4000 in the new MacBook Air 11" and 13". In the previous generation that was max. 256MB for the 11" and 384MB in the 13".

    Is it the same in this generation with the ivy bridge CPUs? I can't find this information anywhere.

    Thanks for your help!
     
  2. dona83 macrumors regular

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    Nov 26, 2004
    Location:
    Coquitlam, BC
    #2
    My wife's 2011 11" says 384MB shared memory... she has 4GB of RAM if that makes a difference.
     
  3. Cliff3 macrumors 65816

    Cliff3

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    Nov 2, 2007
    Location:
    SF Bay Area
    #3
    It looks like it is dynamically allocated up to a maximum of 1,720MB. Since Apple hasn't specified a limit in the specifications, I would guess they left the default behavior in place. The HD3000 has the same limit, but it would appear Apple configured a hard limit for that GPU as they indicate a 384MB limit in their specs for the previous model.

    http://en.wikipedia.org/wiki/Comparison_of_Intel_graphics_processing_units
     
  4. Dwee8le thread starter macrumors member

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    Aug 1, 2010
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    Amsterdam, Holland
    #4
    very interesting. Thanks for your replies.

    If there is no limit set, apparently the MBA can use more than 1,5GB of RAM. A good thing to know. So having 8GB of RAM in total seems to be a good idea. Well, theoretically :) I don't know what the real world situation would be where this GPU would need (or use) that much RAM.
     
  5. Cliff3 macrumors 65816

    Cliff3

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  6. ZZ Bottom macrumors 6502a

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    Apr 14, 2010
    #6
    FYI the limit was not 384mb. This is only because on Macbook Air's the highest RAM available was 4GB. On my 13" MBP with HD 3000 and 8GB RAM, my GPU shows 512mb.

    Someone who has purchased an 8GB configuration will need to chime in. Hopefully they haven't blocked it from allocating 512mb.

    I believe Intel sets the amount allocated. Based on all previous Intel GPUs, think of it as a table. 2gb=256mb, 4gb=384mb, 8gb=512mb, etc
     
  7. Cliff3 macrumors 65816

    Cliff3

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    #7
    Apple's specs for the 2011 MBA indicated that video memory was limited to 384KB. Other models weren't relevant to this topic.
     
  8. NutsNGum macrumors 68030

    NutsNGum

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    Jul 30, 2010
    Location:
    Glasgow, Scotland
    #8
    This is right, the two amounts increase exponentially. 16gb MacBook Pro users either have 768mb or 1gb allocated(can't remember which) I have 512mb on my 8GB Pro.
     
  9. ZZ Bottom macrumors 6502a

    Joined:
    Apr 14, 2010
    #9
    How is the MBP 13" irrelevant. It's made by Apple and had the potential for 8gb, which the new MBA has gained. Therefore it stands to reason that Apple would allow the same RAM to GPU allocation on the new MBA.

    Besides if you're going to tell me off citing Apple specs, at least list them properly. It is 384mb not kb.
     
  10. Cliff3 macrumors 65816

    Cliff3

    Joined:
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    Location:
    SF Bay Area
    #10
    Let me rephrase that - other models were outside the scope of my investigation into an answer to the original question. Apple has not published any information about limits to shared memory allocated to video RAM for the 2012 MBA.
     

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