IBM #EM03 Memory Riser Card for 9040

IBM feature #EM03 is the Memory Riser Card for the IBM Power E950 (machine type 9040, model MR9). Four memory buffer chips are mounted on one riser card, and they provide access to 16 industry-standard (IS) DIMM slots. The slots accept only IBM-supplied DDR4 IS DIMMs of 8 GB, 16 GB, 32 GB, 64 GB or 128 GB. Each buffer chip provides four DDR4 memory ports at a 1,600 MHz signal rate and one 16 MB L4 cache, so one riser card holds 64 MB of L4 cache.

Each processor module supports two riser cards. At least one riser card per module is required, and the second is optional, so the minimum two-processor E950 configuration has two #EM03, one per processor socket. A two-processor module system with four riser cards provides 64 IS DIMM slots and up to 8 TB of memory. A four-processor module system uses eight riser cards, which provide 128 IS DIMM slots, 512 MB of L4 cache and a server maximum of 16 TB.

A riser card is populated with either 8 or 16 IS DIMMs, and every DIMM on one card has the same feature code. The first eight go in the white connectors and the second eight in the black connectors. The riser card slots sit at system board location codes P1-C26 to P1-C29 and P1-C32 to P1-C35. DDR3 and DDR4 CDIMMs from the Power E850 and E850C cannot be reused in the E950.