AB307A HP 2 GB High-Density SyncDRAM Memory Quad

AB307A is the 2 GB high-density SyncDRAM memory module for the HP 9000 rp7420, rp8420, rx7620 and rx8620. The earlier-generation number for the 2 GB size is A6097A. The spare DIMM numbers are A5198-69001, A5198-69101 and A6097-69001. The 2 GB size is the smallest of the four memory products, ahead of AB308A (4 GB), AB309A (8 GB) and AB322A (16 GB).

A cell board must hold at least 2 GB, so AB307A is the minimum amount for one cell. Memory is installed in quads of equal-size DIMMs, in the sequence 1st (0A, 0B, 1A, 1B), 2nd (2A, 2B, 3A, 3B), 3rd (4A, 4B, 5A, 5B) and 4th (6A, 6B, 7A, 7B). A cell board has room for up to 16 DIMMs and 16 GB/s of peak bandwidth.

The system maximum is 128 GB on the rp7420 and rx7620, using eight 16 GB quads, and 256 GB on the rp8420 and rx8620, using sixteen 16 GB quads. The rp7420 and rp8420 share the same 2 GB, 4 GB, 8 GB and 16 GB products, and so do the rx7620 and rx8620.

Performance guidance for a cell: use a multiple of 8 DIMMs, load memory equally across the cell boards, and expect half of the peak bandwidth when only one of the two memory buses is populated. The 16 GB quads cannot be mixed with other sizes, and a partition takes 4 GB DIMMs or the smaller non-stacked sizes, not both.