8pcs. 4GB 1333MHz ECC REGISTER Module CMS brand, CMS is one of the most trusted names in the Computer Memory industry and this product carries a Lifetime Warranty from CMS. Max Memory: 128 GB Sockets: 16 sockets IBM System x3650 M2 4199-XXX IBM System x3650 M2 7947-XXX Our DDR3-1333 modules automatically clock down to 1066MHz and 800MHz depending on which Intel Xeon model is installed and how many module banks are populated. Due to chipset limitations, DDR3 Quad Rank memory is limited to operate at a maximum of 1066MHz. When two Quad Rank modules are installed per bank, the processor will automatically clock them down to 800MHz. System only supports (6) Quad Rank DIMMs per CPU or (12) Quad Rank DIMMs with two CPUs.