HP 313305-B21, 2 GB, 2 x 1 GB, DDR, 266 MHz, 184-pin DIMM HP 313305-B21. Internal memory: 2 GB, Memory layout (modules x size): 2 x 1 GB, Internal memory type: DDR, Memory clock speed: 266 MHz, Memory form factor: 184-pin DIMM, ECC