The G3 iBook has one memory socket and can be upgraded using a 128MB, 256MB or 512MB SDRAM module.
| Standard Memory | 128MB soldered on board | 
| Maximum Memory | 640MB | 
| Memory Expansion (No. of sockets) | 1 Expansion Socket | 
| Memory Expansion | Install 1 at a time | 
| Memory Sizes | 128MB | 256MB | 512MB | 
| Memory Speed (Type) | PC100 |