DIMMs (Dual In-Line Memory Modules) provide a wider data path than SIMMs (Single In-line Memory Modules). DIMMs are "wider" than SIMMs in the amount of data they can carry.

The Power Macintosh 7200, 7500, 8500 and 9500 series computers use 168-pin, 70ns or faster DIMMs, which are 64-bit wide. It takes one DIMM to meet the 64-bit wide data bus requirement. The Power Macintosh 7500, 8500 and 9500 series computers also support memory interleaving when DIMMs are installed in pairs. The Power Macintosh 7200 series computers do not support memory interleaving and can be installed one DIMM at a time.