Is it possible to upgrade vram on Imac Duo

Discussion in 'Mac Pro' started by munkees, Feb 23, 2006.

  1. munkees macrumors 65816

    munkees

    Joined:
    Sep 3, 2005
    Location:
    Pacific Northwest
    #1
    I was wondering if anybody knows if the iMac Duo is GVram is upgradeable after purchase, is it a socket ram or solder.
    for example 128 to 256 or even 512 ?
     
  2. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #2
    No. In general the only way to increase the amount of graphics RAM in ANY modern computer is via a new graphics card (I realise back in the dawn of acclerated 3d cards shipped with sockets for more RAM, this has not been common for at least 6 years). As the iMac does not have a card but the graphics chip and VRAM is soldered to the logic board you are out of luck.

    Edit to add: even if it was socketed you would struggle to get the RAM. VRAM tends to be faster/different spec to normal RAM anyway.
     
  3. munkees thread starter macrumors 65816

    munkees

    Joined:
    Sep 3, 2005
    Location:
    Pacific Northwest
    #3
    But it must be possible to purchase the chips and soldier them on, if you know what you are doing ? I guess the only way to know how is to look at the 128 and the 256 next to each other and see what chips are missing and what else is required like other smaller resistors etc.

    Too much work, for me
     
  4. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #4
    Solder them to where? There are not likely to be solder pads just waiting for the chips. Also they are surface mount so not really solderable by a person.
     
  5. mmmcheese macrumors 6502a

    mmmcheese

    Joined:
    Feb 17, 2006
    #5
    I expect that there would be pads for the RAM because I highly doubt that Apple has 2 different logic board designs for the iMac. There are some people who are good at soldering and can do surface mount soldering, but most people even botch "simple" PCB soldering. The part that will most likely cause the most problems for adventurous hackers is that the RAM is most likely using the ball-grid-array format.

    Wikipedia about BGA
     
  6. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #6
    My thoughts were that they would be using higher density chips for the larger VRAM thus keeping the number of chips on each board the same.
     
  7. mmmcheese macrumors 6502a

    mmmcheese

    Joined:
    Feb 17, 2006
    #7
    That's always a possibility, but I think that's the least of the worries. If you really wanted to, you could probably get your hands on different memory chips to replace the lower density ones (assuming they are).
     
  8. CANEHDN macrumors 6502a

    CANEHDN

    Joined:
    Dec 12, 2005
    Location:
    Eagle Mountain, UT
    #8
    My understanding is it's the same board and chip set. All though Apple stores are not able to upgrade the VRAM. They say only Apple Online can do it. That may be the reason, if the boards are different.
     
  9. topgunn macrumors 65816

    topgunn

    Joined:
    Nov 5, 2004
    Location:
    Texas
    #9
    It is possible that all boards ship with 256MB and they have disabled 128MB. I guess it would depend on which was cheaper; making all boards with an extra 128MB of VRAM, the cost of labor to add 128MB of VRAM, or to have two different logic boards.
     
  10. tjwett macrumors 68000

    tjwett

    Joined:
    May 6, 2002
    Location:
    Brooklyn, NYC
    #10
    interesting. after all, apple had been over and under clocking the G4 for like 5 years to make segments in the product line.
     
  11. Mechcozmo macrumors 603

    Mechcozmo

    Joined:
    Jul 17, 2004
    #11
    Not quite... the eMac is the only really big exception, (along with the Mac Mini I suppose) but overall you can't get a huge performance boost out of a G4 by a quick solder job. Maybe you could get a few extra MHz, but the more likely chance is that you won't because the chip is stable at that speed and won't go higher.

    Chips are made for a certain speed, say, 1.5 GHz for the G4s. But if they fail to hit 1.5 GHz, they are dropped to 1.33 GHz. If they fail that, 1 GHz. That way, you get all the chips you need from one line. If you need more 1 GHz chips, divert some 1.33 or 1.5 chips to that, and that's where overclocking chips lie.
     
  12. tjwett macrumors 68000

    tjwett

    Joined:
    May 6, 2002
    Location:
    Brooklyn, NYC
    #12
    right, i meant more that they were underclocking the faster chips to put into the consumer stuff.
     

Share This Page