These iMac (Late 2006) computers have two SDRAM slots in the bottom of the computer, and comes with at least 512 MB DDR2 SDRAM installed into the top slot.

Although these iMacs will accept up to a 2 GB SO-DIMM in each of the two memory slots, the iMac will only support 3 GB total memory. If you want to maximize the amount of SDRAM in your computer, install a 2 GB SO-DIMM in one slot and a 1GB SO-DIMM in the other.

You can use Small-Outline Dual Inline Memory Modules (SO-DIMMS) that meet all of these criteria:

• PC2-5300
• unbuffered
• nonparity
• 200-pin
• 667 MHz
• DDR2 SDRAM

You can use RAM module sizes of 512 MB, 1 GB or 2GB in the top or bottom slots.

DIMMs with any of the following features are not supported in the iMac (Late 2006) computers: registers or buffers, PLLs, ECC, parity, or EDO RAM.

Note: If you do install a 2 GB SO-DIMM in both the bottom and top memory slots of the computer, the About This Mac window and Apple System Profiler will both show that you have 4 GB of SDRAM installed. However, Activity Monitor and other similar applications will reveal that only 3 GB of SDRAM has been addressed for use by the computer.

Always follow the upgrade instructions for Memory installation as written. Never attempt to remove screws that are not listed in the upgrade instructions.