2pcs 2GB PC2-3200 ECC Registered DIMM single Rank, Make sure the memory you purchase for this system is single rank other wise they will not work.Genuine CMS brand, CMS is one of the most trusted names in the Computer Memory industry and this product carries a Lifetime Warranty from CMS Compatible with: IBM eServer xSeries 346 (8840-xxx) Max Memory: 8 Sockets (4 Banks of 2 Max Memory 16GB Notes: This system can support both the Chipkill and Non-Chipkill memory. When mixing Chipkill and Non-Chipkill kits, the system will not perform the Chipkill function. This chipset supports a maximum of 8 ranks. Kit part numbers consist of two single-rank modules.