The Xserve 2,1 is based on the Intel Xeon 5400 series CPU. The Xserve 2,1 uses a new type of memory called an FB-DIMM. There are eight (8) slots, and the FB-DIMMs must be installed in pairs (2x at a time), or to run 256 Bit Addressing they would be installed in matched quads (4x identical modules). The original 1GB configuration is installed as a pair of two 512MB FB-DIMMs. The system maximum is 32GB with the installation of eight (8) 4GB FB-DIMMs.
Matched Modules: Ramjet kits contain a matched pair of FB-DIMMs. The kit will consist of identical brand/model/spec IC's. They will be from a single batch, and will have matching series numbers. This ensures perfect compatibility.
256 Bit Addressing: The Xserve Intel is capable of addressing a bank of four (4) FB-DIMMs as a single 256-bit memory bus. Having your memory installed as a matched quad will increase your system performance by 5-10%. The Ramjet 1Gig FB-DIMM kit (2x 512mb) can be installed along with the Apple original 1Gig (2x 512mb) to create a 256 bit quad of four (4) 512mb FB-DIMMs.
Please view Apple's installation guide for more information.
Apple's installation guide.
