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HP/Convex SPP2000 (S-Class/X-Class)

Quick Facts
CPU 4-16 PA-8000
180MHz
Caches 1/1MB L1
RAM 16GB
Drives 20 SCSI
Expansion 28 PCI
Bandwidth CPU 7.5GB/s
Mem 15GB/s
I/O 1.9GB/s
XBAR 15.3GB/s
SCI 3.8GB/s
I/O SCSI
Console
SCI (CTI)

Overview

The HP/Convex Exemplar SPP2000 are large scalable PA-RISC computing servers and the direct predecessors of the later HP V-Class (V2200, V2500 et al). Originally developed by Convex, the SPP2000 are based on a crossbar architecture with the central internal switching component connecting the resources to each other by forming matrix connections between the devices’ input and output ports.

A single SPP2000 computer can hold up to sixteen 64-bit PA-8000 processors with 16GB of memory in a single Node — the resulting system is called S-Class (according the HP’s nomenclatura). The SPP2000 can form a large-scale system by connecting single Nodes with SCI links (forming rings) into a larger cluster (Wall) of up to 32 nodes/512 processors. The resulting interconnected systems are called X-Class, in effect consisting of several S-Classes. Interconnected X-Classes are ccNUMA computers, cache-coherent Non-Uniform Memory Access (for a detailed explanation cf. for example the ccNUMA section on the Wikipedia Non-Uniform Memory Access page). Interestingly, the clustering capabilities of the SPP2000’s successors, the V2500, have been reduced significantly — in contrast to the 32-node maximum of SPP2000 clusters, V2500s only can be clustered to groups of four.

As the other Exemplar systems, the SPP2000/S-Class are operated and controlled via so-called teststations, Unix workstations that connect to a central management board in the single nodes which provides booting, system monitoring and diagnostics, and console connections. (These teststations were either IBM RS/6000 AIX systems or later, more common, HP 9000 workstation running HP-UX.)

Introduced: 1996-97 with prices at time of introduction of $189,000 (SPP2000 Node/HP S-Class, four-CPU) to $720,000 to $3 million (SPP2000 Cluster, HP X-Class).

Internals

CPU

Chipset

The SPP2000 is based on the Exemplar crossbar architecture which connects the CPU and I/O to the system main memory.

  1. 8x8 nonblocking crossbar is the central part of the system, it connects the memory to the processor buses and I/O channels. There are eight ports for agents for CPUs and I/O — each agent connects to two CPUs and one I/O channel —, and eight ports for memory. Each crossbar port has a path width of 64-bit, giving it 960MB/s peak bandwidth. The peak raw bandwidth of the crossbar is 15.3GB/s combined. The crossbar in the original Exemplar design (SPP1x00) was built of GaA chips, the SPP2000’s in standard CMOS (1.1M transistors).
  2. Eight Data Mover/Agents attach to the crossbar and provide access for the processors (Runway buses) and I/O controllers (I/O channels) to the memory via the crossbar over a 1.9GB/s datapath (four 32-bit, unidirectional buses from two ports on the Agent connect to two crossbar ports). The I/O channels on the agent have a maximum bandwidth of 240MB/s. Each Agent has two Runway processors buses (64-bit, bidirectional) which have an aggregate raw bandwidth of 960MB/s.
  3. Eight PCI controller connect the 240MB/s I/O channels/PCI buses to the Agents.
  4. Eight Memory controllers attach each one four-way interleaved memory board to the Hyperplane crossbar. Each Memory controller has a bandwidth of 1.9GB/s. The memory controllers probably also interface with the CTI interconnection.

» View a system-level ASCII illustration of the crossbar architecture.

Buses

Memory

Expansion

Drives

Clustering

Multiple Exemplar SPP2000/HP S-Class systems can be connected together to form a single large system, a Wall/X-Class.

External connectors

ROM update

There is an firmware update available for the SPP2000 which contains the latest version 4.2.1.

References

Articles

Operating systems

Benchmarks

Model SPEC95
int		 SPEC95
fp		 SPEC95
rate, int		 SPEC95
rate, fp
SPP2000/S-Class/X-Class 11.8 18.7 92.5
2-CPU: 183
4-CPU: 363
6-CPU: 539
8-CPU: 713
10-CPU: 867
12-CPU: 1012
16-CPU: 1307
 141
2-CPU: 276
4-CPU: 524
6-CPU: 739
8-CPU: 935
10-CPU: 1085
12-CPU: 1220
16-CPU: 1413

Compare these with other results on the Benchmarks page.

Physical dimensions

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