Decommissioned IBM SP2

SP2 at the LRZ (1993-1998)

The SP2 at LRZ was comprised of 6 frames (racks) which contain 77 RS/6000 nodes. Used together, these 77 processors offer :

  • 20.7 GFLOPS peak performance
  • 16.7 GByte Memory
  • 334 GByte disk
  • approx. 14.6 GFLOPS LINPACK HPC-Performance

The SP2 has three types of nodes: Wide Nodes 67 MHz, Wide Nodes 77 MHz, and Thin Nodes 67 Mhz.

The SP2 at LRZ has the following configurations:


    14 Wide Nodes
           67 MHz POWER2 CPU
          256 MByte Memory 
          256 KByte Data Cache
           32 KByte Instruction Cache 
          256 Bit Memory-Bus
          267 MFlOp/s Peak Performance
          230 MFlOp/s Linpack HPC
            2 SCSI-2 fast/wide Adapter
     5 Wide Nodes
           77 MHz POWER2 CPU
            1 GByte Memory (one node with 2 GByte)
          256 KByte Data Cache
           32 KByte Instruction Cache 
          256 Bit Memory-Bus
          308 MFlOp/s Peak Performance
          265 MFlOp/s Linpack HPC
            2 SCSI-2 fast/wide Adapter
    58 Thin-Nodes
           67 MHz POWER2 CPU
          128 MByte Memory
           64 KByte Data Cache
           32 KByte Instruction Cache 
           64 Bit Memory-Bus
          267 MFlOp/s Peak Performance
          180 MFlOp/s Linpack HPC

IBM's POWER Architectures

  • In 1990, IBM announced the RISC System/6000 (RS/6000) family of superscalar workstations and servers
  • POWER (Performance Optimized With Enhanced RISC) architecture
  • An illustration of the processor's logical partitioning is provided here.
    • RISC = Reduced Instruction Set Computer
    • Superscalar = makes possible the simultaneous processing of multiple instructions. Includes:
      • Separate instruction cache (8 KB) and data cache (32 KB or 64 KB)
      • Combined floating point multiply-add instruction which allows a peak MFLOPS rate equal to two times the MHz rate while using a single functional unit.
      • Zero-cycle branches
      • Simultaneous running of fixed- and floating-point operations.
      • Overlapped running of register-register operations and load and store commands.
    • 32 general purpose registers (32 bit)
    • 32 floating point registers (64 bit - double precision)
    • 128-bit memory addressing
    • Different models depending upon clock rates, size of data cache, etc.
  • Continued improvements in the POWER processor architecture have led to the POWER2 processor.