4GB 2 X 2GB PC2-5300F 667MHz 240 pin DDR2 SDRAM ECC Fully Buffered FB DIMM Server Low Power Memory for HP Workstation XW8600 (PARTS-QUICK BRAND). Equivalent to HP Part Numbers: 397413-B21, 442823-B21,
A-Tech 16GB (4x4GB) ECC RAM for Gigabyte Gigabyte GA GA-3CESL-RH | DDR2 667MHz ECC RDIMM PC2-5300 2rx4 Registered DIMM Server Memory Kit at Amazon.com