iMac (Mid 2007) and later: Installing or replacing memory
Summary
Learn how to install additional memory or replace the memory in your iMac (Mid 2007) or later computer.
Products Affected
iMac (20-inch, Mid 2007), iMac (24-inch Mid 2007), iMac (24-inch, Early 2009), iMac (20-inch, Early 2009), iMac (24-inch, Early 2008), iMac (20-inch, Early 2008)
The iMac (Mid 2007) and later computers have two side-by-side Synchronous Dynamic Random-Access Memory (SDRAM) slots in the bottom of the computer.
The maximum amount of random-access memory (RAM) you can install in the computer:
| Computer | Memory Type | Maximum Memory |
| iMac (Mid 2007) | DDR2 | 4GB (2x2GB) |
| iMac (Early 2008) | DDR2 | 4GB (2x2GB) |
| iMac (Early 2009) | DDR3 | 8GB (2x4GB) |
You can use 1 or 2GB RAM module in each slot for iMac (Mid 2007) and iMac (Early 2008). Use 1, 2, or 4GB modules in each slot for the iMac (Early 2009).
Use Small Outline Dual Inline Memory Module (SO-DIMM) that meet all of these criteria:
| iMac (Mid 2007) | iMac (Early 2008) | iMac (Early 2009) |
| PC2-5300 | PC2-6400 | PC3-8500 |
| Unbuffered | Unbuffered | Unbuffered |
| Nonparity | Nonparity | Nonparity |
| 200-pin | 200-pin | 204-pin |
| 667MHz DDR2 SDRAM | 800MHz DDR2 SDRAM | 1066MHz DDR3 SDRAM |
DIMMs with any of the following features are not supported:
- Registers or buffers
- PLLs
- Error-correcting code (ECC)
- Parity
- Extended data out (EDO) RAM
To install memory into the bottom slot, follow these instructions:
- Turn your computer off by choosing Shut Down from the Apple menu.
- Disconnect all cables and the power cord from your computer.
- Place a soft, clean towel or cloth on the desk or surface to prevent scratching the LCD display.
- Hold the sides of the computer and slowly lay the computer face-down.
- Using a Philips screwdriver, remove the RAM access door in the bottom of the computer
.
- Remove the access door and set it aside.
- Untuck the tab in the memory compartment. If you are replacing a memory module, untuck the tab and pull it to eject any installed memory module.
- Insert your new or replacement RAM SO-DIMM into the empty slot, keeping in mind the orientation of the keyway of the SO-DIMM as shown above.
- Once inserted, press the DIMM up into the slot. You'll hear a slight click when the memory is seated correctly.
- Tuck the tabs above the memory DIMMs, and re-install the memory access door.
- Stand the computer in its upright position, reconnect the power cord and all other cables to the computer, then start the computer.
Additional Information
For more information about the SDRAM in the iMac (Mid 2007) computer, see this article.