HP 512MB PC100 SDRAM, 0.5 GB, 1 x 0.5 GB, DRAM, 100 MHz, 168-pin DIMM HP 512MB PC100 SDRAM. Internal memory: 0.5 GB, Memory layout (modules x size): 1 x 0.5 GB, Internal memory type: DRAM, Memory clock speed: 100 MHz, Memory form factor: 168-pin DIMM, ECC