IBM #EM8W 256 GB (4×64 GB) CDIMMs, 1600 MHz DDR4 DRAM for 9080 and 9119

IBM feature #EM8W is a 256 GB (4 x 64 GB) set of CDIMMs, 1600 MHz, DDR4 DRAM, for the IBM Power E870 and Power E880 (machine type 9119) and the Power E870C and Power E880C (machine type 9080). Each memory feature provides four CDIMMs, which make one memory quad, and CDIMMs are custom DIMMs that enhance memory performance and reliability. #EM8W is the DDR4 version of the 256 GB feature #EM8L, which uses DDR3 DRAM.

Each system node has 32 CDIMM slots and takes a maximum of eight memory features. Each POWER8 processor has two memory controllers, and each controller must have at least a pair of CDIMMs attached, so every installed processor needs at least one memory quad and can have only four or eight CDIMMs attached. All CDIMMs connected to the same processor must be identical, but different CDIMM sizes can be mixed between processors. The CDIMM capacity can be upgraded on demand, at least 50% of the installed memory must be activated through memory activation features, and the minimum installed memory of 256 GB therefore requires 128 GB active.

On the Power E870C and Power E880C the DDR4 CDIMMs cannot be mixed with another CDIMM size on the same system node or server, 50% of the memory slots must be filled, and firmware 840.12 is the required minimum level.