Acer 512MB DDR II PC3200 ECC Registered, 0.5 GB, DDR2, 400 MHz, 240-pin DIMM Acer 512MB DDR II PC3200 ECC Registered. Internal memory: 0.5 GB, Internal memory type: DDR2, Memory clock speed: 400 MHz, Memory form factor: 240-pin DIMM, ECC