SIMMS MEMORY 72-pin SIMMs are commonly found in older desktop computers, such as the 486 and early Pentium models. Each 72-pin SIMM provides a 32-bit data path, so they can be installed singly in 32-bit systems (486 models) but must be installed in pairs in 64-bit systems (Pentium and Athlon models). 72-pin SIMMs are available in FPM Non-Parity, EDO or FPM Parity.