The Intel iMac is built with the Intel Core Duo Processor. It has two memory sockets and can be upgraded to 2GB maximum using (DDR2-667 DIMMs) and if both are loaded with an equal amount of RAM, you can take advantage of the system's dual-channel memory interface for an additional performance boost.
Standard Memory  | 
512MB Removable  | 
Maximum Memory  | 
2GB  | 
Memory Expansion (No. of sockets)  | 
2 Expansion Sockets  | 
Memory Expansion  | 
Install 1 at a time  | 
Memory Sizes  | 
512MB | 1GB  | 
Memory Speed (Type)  | 
PC2-5300 DDR2-667  |