Computer memory form factor

thumb|Two types of DIMMs: a 168-pin SDRAM module (top) and a 184-pin [[DDR SDRAM module (bottom). The SDRAM module has two notches (rectangular cuts or incisions) on the bottom edge, while the DDR1 SDRAM module has one. Also, each module has eight RAM chips, but the lower one has an unoccupied space for the ninth chip; this space is occupied in ECC DIMMs.]]

thumbnail|30-pin, proprietary Apple 68-pin, and 72-pin SIMMs

single in-line pin package, a type of computer memory

form factor for replaceable laptop RAM