JEDEC JESD82-30.01 PDF

The Load Reduced DIMM (LRDIMM) Memory Buffer (MB) supports DDR3 SDRAM main memory. The Memory Buffer allows buffering of memory traffic to support large memory capacities. Unlike DDR3 Register Buffer (SSTE32882), which only buffers Command, Address, Control and Clock, the LRDIMM Memory Buffer also buffers the Data (DQ) interface between the Memory Controller and the DRAM components.