AB308A HP Integrity 4 GB High-Density SDRAM Memory

AB308A is the 4 GB high-density SDRAM memory quad for the HP Integrity rx7620 and HP Integrity rx8620, the same quad that the HP 9000 rp7420 and rp8420 use. The single-DIMM spare is A6098-69101, a 1 GB high-density SDRAM DIMM, so the quad is four 1 GB (1024 MB) DIMMs. The earlier-generation number for this quad size is A6098A.

The rp7420 and rp8420 share the same 2 GB, 4 GB, 8 GB and 16 GB memory products with the rx7620 and rx8620: AB307A, AB308A, AB309A and AB322A. The DIMMs are custom designed by HP, with 36x4 SDRAM chips qualified to run at 125 MHz.

Every quad is four DIMMs of equal density, and the minimum for a cell is 2 GB. Using only the 1024 MB DIMM size, the maximum capacity is 32 GB on the rp7420 and rx7620 and 64 GB on the rp8420 and rx8620. The system maximum with the largest quads is 128 GB on the rp7420 and rx7620 (eight 16 GB quads) and 256 GB on the rp8420 and rx8620 (sixteen 16 GB quads).

On each cell board the quads are placed in sequence: 1st (0A, 0B, 1A, 1B), 2nd (2A, 2B, 3A, 3B), 3rd (4A, 4B, 5A, 5B), 4th (6A, 6B, 7A, 7B). Load memory equally across the cell boards present. Populating only one of the two memory buses of a cell board delivers half of the peak memory bandwidth, so a multiple of 8 DIMMs is the target for each cell.