16GB Total memory using 4pcs 4GB PC2-5300 DDR2-667 240-pin Registered ECC SDRAM DIMM. This computer can use 3200, 4200 and 5300 dimms CMS brand, CMS is one of the most trusted names in the Computer Memory industry and this product carries a Lifetime Warranty from CMS. Tyan Thunder n3600M (S2932G2NR), n3600M (S2932WG2NR) Maximum Memory: 32 GB Expansion: 4 Sockets (2 Banks of 2) per CPU 8 Sockets Total Mfgr's System P/N's: S2927 Comments MODULES MUST BE ORDERED AND INSTALLED IN PAIRS for Dual Channel mode. Mixing DDR2-533 Registered DIMMs with DDR2-667 Registered with Parity DIMMs is not recommended. Mixing x4 and x8 modules is allowed, however not within the same bank.