Ceased trading.

Overview of Organization:

Organisation noted for production of the Elxsi 6400 system.

Platforms Documented:

Contact Address:

(no longer useful)
2334 Lundy Place
San Jose, CA 95131-1873
Tel 408-942-0900
FAX 408-945-5875

Bridge House
Tel 0932-253081
FAX 0932-247199

See Also:

ELXSI 6400

Overview of Platform:

Parallel Processor/Bus Architecture

The System 6400 features a high-speed 64-bit bus architecture. Multiple CPUs, IOPs, and memory modules, based on high-density LSI components using ECL technology, plug directly into the bus and communicate using microcoded messages. Modules, operating in parallel, perform processing, I/O, and memory operations simultaneously.


Each CPU has 3 boards, rated at 7 MWhets on M6410 CPU and at 12MWhets on M6420 CPU.

The system is a stand-alone system with a high-performance I/O system capable of a peak of 64 Mbytes/sec. Various controllers can be attached to the I/O processor including disks, tapes, asynchronous terminals, DRII, VME, Ethernet, X.25, and printers. Networking is available over Ethernet using TCP/IP and/or Community (DECnet), over X.25 using Coloured Books, or over DRII to Hyperchannel.

Compute Hardware:

Interconnect / Communications System:

Memory System:

The main memory is accessed through the fast bus. The bus is a 64-bit wide channel providing a gross bandwidth of 320 Mbytes per second, giving a transfer rate of 160-213 Mbytes/second.

Benchmarks / Compute and data transfer performance:

The peak rating of the machine is 250 mips. A single Pegasus processor performs at 10 Mflops on the LINPACK benchmark, and there are up to 10 processors in a single configuration. A 12-processor M6420 is rated at 120 mips.

Operating System Software and Environment:

Multiple operating systems can operate concurrently on the System 6400. Virtual memory management, load balancing, and process migration are incorporated as a base for all operating systems including EMBOS (ELXSI proprietary Message Based Operating System), ports of AT\&T System V.3 and BSD 4.3, and EMS (ELXSI's VMS-like environment).

ENIX System V runs a native port of UNIX System V.3 in a multiple processor environment. It migrates UNIX processes across multiple CPUs, performing load balancing and resource allocation automatically. ENIX System V runs multiple copies concurrently on single or multiple CPUs. Shared libraries, C and Bourne shells, and TCP/IP over Ethernet are supported.

ENIX BSD runs a native port of 4.3 BSD, allows 2 Gbytes per process, and is efficient on memory-intensive applications. Again multiple copies run concurrently on single or multiple CPUs, and there is automatic load balancing and resource allocation.

The EMS system includes ECL, which interprets and executes VMS interactive commands and command files; ERT, which provides VMS applications with system and utility support during compilation and execution; and EDT, which is an interactive text editor.

From any of the operating systems, programmers can access parallel intrinsics at both the micro and macro level. Functions included are parallel execution of subroutine-level tasks, parallel execution of loops by dividing loops into microtasks and executing microtasks in parallel, automatic load balancing of parallel processes, non-cacheable or cacheable data sharing, and simultaneous parallel processing and general purpose multiprocessing.

Fortran 77, Pascal, COBOL 74, C, MAINSAIL, Franz LISP, Common Lisp, Simscript, and Ada. DEC Fortran extensions are supported. Auto-vectorizing, and a full suite of debugging facilities, including a symbolic debugger and monitoring utilities, are available.

Networkability/ I/O System / Integrability / Reliability / Scalability:

The system can be configured with 1-12 CPUs, 1-4 IOPs, and up to 2 Gbytes of main memory. The CPUs and IOPs have their own local cache of up to 1 Mbyte of high-speed RAM. Each IOP can support up to 32 I/O controllers. The SECDED memory is interleaved 2-way internal and up to 16-way external.

Notable Applications / Customers / Market Sectors:

The first machine based on a 6410 CPU was delivered in 1983. The 6420 CPU was first delivered in 1986, and the 6460 was announced February 1988 and is scheduled for delivery in 4Q 1988. ELXSI now has over 200 CPUs installed in over 100 systems at 80 customer sites.

Overall Comments: