Cray CS6400
| Company type | Division |
|---|---|
| Industry | Computer hardware |
| Predecessor | Cray Research |
| Founded | 1993 |
| Fate | Sold to Sun Microsystems after acquisition by Silicon Graphics in 1996 |
| Products | Cray Superserver 6400 (CS6400) |
| Parent | Cray Research |
The Cray Superserver 6400 (CS6400) is a multiprocessor server platform introduced in 1993 by Cray Research Superservers, Inc., a division of Cray Research, which has since been discontinued. It was also sold under the name Amdahl SPARCsummit 6400E.
During its development phase, the system was known by the codename SuperDragon. The CS6400 followed the earlier Cray S-MP, another SPARC-based architecture. It utilized the XDBus, a packet-switched inter-processor communication bus originally created at Xerox PARC and employed in Sun Microsystems’ SPARCcenter 2000 and SPARCserver 1000 machines. The server supported SuperSPARC-I processors running at 60 MHz or SuperSPARC-II processors at 85 MHz, along with memory capacity scaling up to 16 GB.
The CS6400 shared both its SuperSPARC CPUs and the Solaris operating environment with Sun servers. Its design allowed configurations ranging from 4 up to 64 processors connected via quad XDBus channels operating at 55 MHz. This configuration far surpassed the SPARCcenter 2000’s maximum of 20 processors on dual XDBus channels and the SPARCserver 1000’s limit of 8 processors on a single XDBus.
A notable feature of each CS6400 system was the inclusion of an external System Service Processor (SSP), which was a SPARCstation equipped with a JTAG interface responsible for handling internal bus control and configuration tasks. While the SSP mainly facilitated configuration updates, some later systems such as the Sun Enterprise 10000 relied entirely on their SSP for operation.
Following Silicon Graphics’ acquisition of Cray Research in 1996, the Superserver division—then known as Cray Business Systems Division—was sold to Sun Microsystems. This deal included Starfire, the successor to the CS6400 under development at that time, which eventually became the Sun Enterprise 10000.