iMac (21.5-inch, Late 2013)

iMac (21.5-inch, Late 2013) computers have two internal SDRAM slots inside the computer. The computer comes with at least 8 GB DDR3 SDRAM installed as two 4 GB DIMMs into two slots. The maximum amount of RAM the computer supports is 16 GB (an 8GB SO-DIMM in each slot).

You can configure your iMac (21.5-inch, Late 2013) with the amount of SDRAM you'd like when you're ordering it. Installed RAM module sizes can be 4 GB or 8 GB in each slot.

The memory DIMMs for iMac (21.5-inch, Late 2013) computers are not user-accessible. Visit an Apple Retail Store or Apple Authorized Service Provider if you need to replace your iMac (21.5-inch, Late 2013) computer's DRAM.

iMac (27-inch, Late 2013)

iMac (27-inch, Late 2013) computers have four SDRAM slots in a compartment located on the rear of the computer. The computer comes with at least 8 GB DDR3 SDRAM installed as two 4 GB DIMMs into two slots. The maximum amount of RAM you can install in your computer is 32 GB (an 8 GB SO-DIMM in each slot). 

You can use any small-outline dual inline memory modules (SO-DIMMS) that meet all of these criteria:

• PC3-12800
• Unbuffered
• Nonparity
• 204-pin
• 1600 MHz
• DDR3 SDRAM

You can use RAM module sizes of 4 GB or 8 GB in each slot. Memory sold by the Apple Online Store is guaranteed to be compatible with your Macintosh.

DIMMs with any of the following features do not work in iMac (27-inch, Late 2013) computers:

• Registers or buffers
• PLLs
• ECC
• Parity
• EDO RAM

Always follow the upgrade instructions for memory installation. See iMac (27-inch, Late 2012 and later): Installing or replacing memory for details.