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,
Crucial 4GB Single DDR2 667MHz (PC2-5300) CL5 SODIMM 200-Pin Notebook Memory Module CT51264AC667 at Amazon.com
8GB Kit 2 X 4GB DDR2 Server Memory Upgrade for Dell PowerEdge 2950 III SDRAM ECC Fully Buffered FB DIMM PC2-5300 240 pin 667MHz RAM (PARTS-QUICK Brand) at Amazon.com