Another memory upgrade question (but a bit differet)

Discussion in 'MacBook Air' started by MBA101, Aug 7, 2014.

  1. MBA101 macrumors newbie

    Joined:
    Aug 7, 2014
    #1
    Say I had the ability and know-how to de-solder and solder on new DRAM chips to my MBA logic board. And say I have easy access to bigger DRAM chips. Does anyone know how to tell the MBA that bigger chips are now available for it to use? Is there an EEPROM to store the SPD data or is this info stored elsewhere (i.e. UEFI)?
    I seem to recall reading that someone tried it a while back, but I've searched everywhere and can't locate anything. Does anyone know? Thanks.
     
  2. Groovemaster17 macrumors member

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    Aug 7, 2012
  3. mad3inch1na macrumors 6502a

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    Oct 21, 2013
    #3
    What do you mean by "bigger" chips? Do you mean physically larger or higher storage? If you actually know what you are doing, I guess go for it, but be warned that there is a high chance that you will fry your logic board in the process, which is easily $400. If you are upgrading to 8GB of RAM, I would only do it if

    1. You were on the original design team for the MBA, and
    2. You have the exact modules from the high end model

    Other than that, you are very likely to incur about $500 worth of damage to your MBA. If you really think you can pull it off, I think you would be the first person to at least publicly do it. As long as you feel comfortable throwing $500 away, just make sure to upload a progress video :).

    Matt
     
  4. capathy21 macrumors 65816

    capathy21

    Joined:
    Jun 16, 2014
    Location:
    Houston, Texas
    #4
    The fact that you are asking means you are definitely not qualified to even dream of attempting it. As I understand, it is soldered to the board from both sides so apart from destroying the board, I'm not sure how you could pull it off.
     
  5. MBA101 thread starter macrumors newbie

    Joined:
    Aug 7, 2014
    #5
    By bigger I mean more density. I do actually know what I'm doing and I've already pulled (de-soldered) one of the BGA DRAMs off. Physically replacing the rest of the DRAMs will not be an issue.

    The hard part is figuring out how to tell the CPU that more memory is available for it to use. I haven't identified an EEPROM anywhere near the memory. It's not in a standard 8 pin MLP or TSSOP8 package, at least none that I can find. I'm hoping someone knows where it is so I can rewrite the SPD data (which I also know how to do). If someone knows where this SPD data is stored and is willing to share that info, I think this is easily doable.

    Again, I have the necessary equipment to replace BGAs. I'm looking for information about where the memory configuration data (i.e. SPD) is stored. Is it in the UEFI or is there an EEPROM?
     
  6. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #6
    I'm wondering if you would even need to do anything to the EFI at all. On previous MacBooks where you could just pop in more memory, you just did the upgrade and started up and the added memory was recognized. Not to say the Air is the same way, but it might be.

    Please let us know how you make out with this. I'm really curious. :)
     
  7. MBA101 thread starter macrumors newbie

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    Aug 7, 2014
    #7
    That works because modules have an EEPROM on them. Since these are soldered directly to the logic board, the SPD data has to be stored elsewhere. CPUs can't auto detect how much memory is connected, they have to read the SPD info.
     
  8. Weaselboy Moderator

    Weaselboy

    Staff Member

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    Jan 23, 2005
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    California
    #8
    Learning has occurred today. :D
     
  9. Meister Suspended

    Meister

    Joined:
    Oct 10, 2013
    #9
    I would not attempt this, but I am pretty sure it is possible.
    Like weasle mentioned I think the ram should be recognized by itself.

    This takes the whole ram debate to whole other level.
    You must need ram really bad :D

    Please post how this turned out and try to make good pictures of the process! That would be awesome.
     
  10. MBA101 thread starter macrumors newbie

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    Aug 7, 2014
    #10
    What makes you say that the RAM should be recognized by itself? How would the CPU know that bigger DRAMs are there now? Is there something different about the Macbook Air that makes it able to detect the memory density?
     
  11. Alekto macrumors regular

    Joined:
    Nov 15, 2012
    Location:
    Tokyo
    #11
    Are you going to attempt a CPU upgrade too? That would be awesome to see from a purely showboating point of view :)
     
  12. Meister Suspended

    Meister

    Joined:
    Oct 10, 2013
    #12
    I assumed that since with all ram upgrades i have ever done the machine recognized them without issues the mba would be the same.
    With what you are attempting to do I am out of my depth!
     

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