4 Replies Latest reply: Jan 2, 2014 7:18 PM by Csound1
Rick Carlton Level 1 Level 1 (10 points)

I now have 2 GB chips in all 4 slots.

 

I want to change 2 of them to 4 GB chips.

 

Do I put the 4 GB chips in the upper or lower slots?

 

TIA


iMac, OS X Mavericks (10.9.1), 2.7 Ghz I5 core
  • mende1 Level 10 Level 10 (91,380 points)

    In order to take advantage of Dual Channel, remove the modules at the top or at the bottom. If you remove the modules at the left or the right, you will lose Dual Channel and you may lose memory performance

  • Rick Carlton Level 1 Level 1 (10 points)

    OK - the Apple repair guy put them in today - when I pull up "About this Mac" it shows this:

     

    BANK0/DIMM0     4GB

    BANK1/DIMM0     4GB

    BANK0/DIMM1     2GB

    BANK1/DIMM1     2GB

     

    Memory Slots:

     

      ECC:          Disabled

     

    BANK 0/DIMM0:

     

      Size:          4 GB

      Type:          DDR3

      Speed:          1333 MHz

      Status:          OK

      Manufacturer:          0x80AD

      Part Number:          0x484D54333531533643465238432D48392020

      Serial Number:          0x0C55FB51

     

    BANK 1/DIMM0:

     

      Size:          4 GB

      Type:          DDR3

      Speed:          1333 MHz

      Status:          OK

      Manufacturer:          0x80AD

      Part Number:          0x484D54333531533643465238432D48392020

      Serial Number:          0x0C15F1BD

     

    BANK 0/DIMM1:

     

      Size:          2 GB

      Type:          DDR3

      Speed:          1333 MHz

      Status:          OK

      Manufacturer:          0x802C

      Part Number:          0x384A53463235363634485A2D314734443120

      Serial Number:          0xFD55D584

     

    BANK 1/DIMM1:

     

      Size:          2 GB

      Type:          DDR3

      Speed:          1333 MHz

      Status:          OK

      Manufacturer:          0x802C

      Part Number:          0x384A53463235363634485A2D314734443120

      Serial Number:          0xFD55D585

     

    Does this look right to keep the Dual Channel?

     

    Also, what doe "ECC: Disabled" mean? Is this anything to worry about? I don't know what ECC is or whether it means something to Dual Channel or faster/better operation.

     

    All help appreciated!!   Rick

  • Frank Caggiano Level 7 Level 7 (25,720 points)

    The configuration looks ok. The ECC Disabled is normal and not a concern.

     

    ECC is a type of error detection/correction that some memory systems use, Mac's don't use it (except for the Mac Pro, I believe)

  • Csound1 Level 8 Level 8 (44,285 points)

    ECC Ram is almost always used in Servers. PC's and Macs (possibly except for the Mac Pro) neither need nor can use it.