8GB KIT (2 x 4GB) For HP-Compaq Workstation Series xw4600 xw4600/CT. DIMM DDR2 ECC Unbuffered PC2-6400 800MHz Dual Rank RAM Memory. Genuine A-Tech Brand. 8GB KIT (2 x 4GB) DIMM DDR2 ECC Unbuffered PC2-6400 800MHz Dual Rank RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For HP-Compaq Workstation Series. (See Compatibility List Below)