A6100A HP 8 GB SDRAM Memory Quad (2048 MB DIMMs)

A6100A is the 8 GB high-density SDRAM memory upgrade, a set of four 2 GB (2048 MB) DIMMs. It is the rp7410 number for the 8 GB quad on the HP 9000 rp7420, the rp7410-8 number on the HP Integrity rx7620, and the rp8400 number on the rp8420 and rx8620. AB309A is the number for the same 8 GB quad size on the current servers.

The quad is four DIMMs of equal size. If A6100A is the only DIMM size in the system, the maximum capacity is 64 GB on the rp7420 and rx7620 and 128 GB on the rp8420 and rx8620. The minimum memory is 2 GB per cell, and the quad is the 8 GB density between the 4 GB quad and the 16 GB quad of four 4096 MB DIMMs.

On a cell board, quads are installed in the sequence 1st (0A, 0B, 1A, 1B), 2nd (2A, 2B, 3A, 3B), 3rd (4A, 4B, 5A, 5B), 4th (6A, 6B, 7A, 7B). Each cell board supports up to 16 DIMMs, which is four quads, with a peak memory bandwidth of 16 GB/s. For best performance a cell carries a multiple of 8 DIMMs, because both memory buses are populated with 8 DIMMs.

High-density quads such as this one leave slots free for growth. On the rx7620 the 8 GB quad made of 2 GB DIMMs is the size recommended to minimize memory slot constraints, and the rp7420 recommends the 4 GB, 8 GB and 16 GB quads for the same reason. Memory is loaded equally across the available cell boards.