Overview of Organization:
Organisation noted for production of the Elxsi 6400 system.
(no longer useful)
2334 Lundy Place
San Jose, CA 95131-1873
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
Each CPU has 3 boards, rated at 7 MWhets on M6410 CPU and at 12MWhets
on M6420 CPU.
Up to 12 CPUs.
64-bit wide data paths.
50-nsec cycle time.
6410 16-Kbyte, 2-way set associative cache
6420 64-Kbyte, 2-way set associative cache (100-nsec access time).
16 sets of 64-bit general-purpose registers.
IEEE floating-point arithmetic.
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
- M6460 (Pegasus)
- Each CPU has 2 boards, rated at 57 MWhets and 10 Mflops on LINPACK.
- Up to 10 CPUs
- 64-bit wide data paths.
- 31.25-nsec cycle time.
- 1 Mbyte of cache allocatable dynamically by the users.
- 16 sets of 64-bit general-purpose registers.
- Five-stage pipelining with optimization.
- IEEE floating-point arithmetic.
- Fully compatible with 6410 and 6420.
- Dual floating-point units.
- External interrupt lines for real-time processing.
Interconnect / Communications 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
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
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.