iMac (27-inch, Late 2012 and later): Installing or replacing memory

Learn how to install additional memory or replace the memory in your iMac (27-inch, Late 2012) and iMac (27-inch, Late 2013) computer.

General Information

The iMac (21.5-inch, Late 2012) and iMac (21.5-inch, Late 2013) has no user-accessible memory compartment. Memory replacement on the iMac (21.5-inch, Late 2012) and iMac (21.5-inch, Late 2013) must be done by an Apple Retail Store or Apple Authorized Service Provider.

iMac (27-inch, Late 2012) and iMac (27-inch, Late 2013) computers have four SO-DIMM DDR3 SDRAM (Synchronous Dynamic Random-Access Memory) slots located in a compartment on the rear of the computer just above the AC power cord receptacle. You can use 4 GB or 8 GB SDRAM SO-DIMMs of 1600 MHz DDR3 memory in each slot. The maximum amount of memory you can install in the computer is 32 GB (an 8 GB SO-DIMM in each slot).

Only use SO-DIMMs that meet certain criteria.


  1. Turn off your computer by choosing Shut Down from the Apple () menu.
  2. Disconnect the power cord and all other cables from your computer.
  3. Place a soft and clean towel or cloth on the desk or other flat surface to prevent scratching the display.
  4. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
  5. Open the memory compartment door by pressing the small gray button located just above the AC power port.
  6. The memory compartment door will open as the button is pushed in. Remove the compartment door and set it aside.

    Note: There is a diagram on the underside of the compartment door showing the memory cage levers and the orientation of the DIMM. The orientation is different between the iMac (27-inch, Late 2012) and iMac (27-inch, Late 2013) computers.
  7. Locate two levers on the right and left sides of the memory cage. Push the two memory cage levers outward to release the memory cage.
  8. Once the memory cage is released:, pull the memory cage levers toward you, allowing you to access each individual DIMM slot.
  9. Remove a DIMM by pulling the module straight up and out. Note: Each DIMM contains a key slot that prevents incorrect installation of the DIMM. The DIMM orientation is different between the iMac (27-inch, Late 2012) and iMac (27-inch, Late 2013) as shown below.

    iMac (27-inch, Late 2012) DIMM Orientation

    iMac (27-inch, Late 2013) DIMM Orientation
  10. Replace or install a DIMM by setting it down into the slot and pressing firmly until you feel the DIMM click into the slot.
  11. Once you have all of your DIMMs installed, push the memory cage levers back into the housing until they subtly click back into place.
  12. Replace the memory compartment door. There is no need to depress the compartment door release button when replacing the compartment door.
  13. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

Learn more

See iMac (Mid 2007) and later models: About new startup tones if you hear tones after installing or replacing memory.

See iMac: How to remove or install memory for information on memory installation in additional iMac models.

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