4GB Kit [2x2GB] ECC Registered 2Rank RAM Memory Upgrade for the Dell Precision Workstation 670 (DDR2-400, PC2-3200) Guaranteed Compatible for the Dell Precision Workstation 670 Speed up your system with up to 16.0GB of memory! Important notes on this system: This chipset supports a maximum of 8 ranks. Dual Rank modules are only supported in the first two banks, sockets DIMM_1 through DIMM_4. Sockets DIMM_5 and DIMM_6 do not support Dual Rank modules and will be disabled if Dual Rank modules are installed in sockets DIMM_3 and DIMM4. If you need further explanation, or have questions, give us a call at the number below! Lifetime Replacement Warranty! Will ship the same day when ordered at or before 4pm EST! All others ship next day! Fully-staffed call center to help with installation or inquiries! Call 866-335-1355 with questions or for help!