CP-PACS Hardware Implementation
The CPU chip of CP-PACS is fabricated usng 0.3 micron CMOS semiconductor technology. The chip size is 15.7mm x 15.7mm. The floor plan of the chip is shown below. The PVP-SW feature is implemented with 128 floating point registers occupying the top left block together with floating point execution units.
Three chips, namely the CPU, the storage controller (SC) and the network interface adapter
(NIA), are mounted in-line on a ceramic multi-chip module of size
5.7cm x 5.7cm, which is shown below. These chips are the three white squares, the top one
is the CPU, the central one is the SC and the bottom one is the NIA.
The SC and NIA chips are fabricated using 0.5 micron
CMOS gate-array technology. The twelve gold pieces on the module are the
second-level cache memory chips.
Eight PU modules together with their DRAM memory are mounted on a board
of size 45.6cm x 62.5cm. The central white piece of each of the eight sections
in the picture below is the PU module, now with fins for air-cooling. The
other white pieces are main memory address/data control units. The black
pieces are DIM modules of 4Mbit DRAM, 64MByte for each PU. Each board has
two more chips for the crossbar switches in the x direction, and one chip for
the clock distributer.
Sixteen PU boards and one IOU board are placed vertically on a back plane, and two back planes, one on top of the other, are housed in a cabinet.
A Crossbar switch in the y direction is mounted on the backplane in the cabinet. Crossbar switches in the z direction are mounted on separate boards, which are housed in separate cabinets.
A schematic floor plan of the cabinets are shown below. The squares labeled "PU" represent cabinets housing the PU and IOU's, and those labeled "Z" are for the crossbar switches in the z direction. The cabinets labeled "IOA" contain I/O adapters. The RAID-5 distributed disk system, placed a few meters from the CP-PACS, is connected to the IOU's by a SCSI-II bus through adapters in the IOA cabinets.
The system is cooled by air drawn in from beneath the cabinets.
