
\noindent
{\bf
NEC SX-JA, SX-1EA, SX-1A and SX-2A
}

\noindent
{\bf
Vector Register Architecture
}

\vspace {.1in}
\noindent
{\bf Architecture:}
The SX-A Series has two types of processor: up to two Central
Processors (CP) and one Arithmetic Processor (AP) sharing
the main memory.  The CP is a front-end mainframe processor
where system control programs and user programs run.  The
AP is a kind of Fortran engine dedicated to execution of
user programs.  Although the SX runs in stand-alone mode, NEC
supports its ACOS series mainframes and also IBM mainframe
connections.

\vspace {.1in}
\noindent
AP Architecture
\begin{itemize}
\item RISC-based scalar architecture

\item 16 vector arithmetic pipelines:  four identical sets
each with an add, multiply, logical, and shift pipe.

\item 1000 gate LSIs with 250 picosecond gate delay.

\item Circuits are packaged 36 to a module, and 12 modules
     to a board.

\item1 Kbit bipolar memory with 3.5 nsec cache memory
     access time.

\item 1024 Mbyte memory (512-way interleaving) with 8 Gbyte
     extended memory.

\item 256 Kbit static MOS memory chip with 40 nsec access
     time, giving a memory-to-register rate of 11 Gbyte/sec.

\item Register-to-register machine with 80 (on the SX-2)
     Kbytes of vector registers and four sets of four
     decimal units yielding a maximum result rate of 8 flops
     per cycle.
\end{itemize}

\vspace {.1in}
\noindent
Scalar arithmetic is pipelined (128 scalar registers) and
operates in parallel with vector units.  The NEC scalar
cycle time is the same as the vector, and is segmented and
pipelined to allow more than one pair of operands to
progress through the same functional unit concurrently.

\vspace {.1in}
\noindent
CP Architecture

\begin{itemize}
\item An extension of the NEC mainframe computer, rated at
     maximum 37 mips (4 types of CP prepared).

\item Virtual storage support.

\end{itemize}
\newpage
\noindent
{\bf Configuration:}
A summary of the four machines is given in the following
table:

\vspace{.15in}
\begin{center}
\begin {tabular} {r r r r r}
  &         SX-1EA   &  SX-1A  &   SX-2A &   SX-JA \\
 Number Pipes &    4 v-pipe & 8 v-pipe & 16 v-pipe & 4 v-pipe \\
 Length regs   &   20K v-reg & 40K v-reg & 80K v-reg & 20K v-reg \\
\end{tabular}
\end{center}
\vspace{.15in}


\vspace {.1in}
\noindent
Can be used as stand-alone machine or can link to other
equipment through a hyperchannel.  Separate I/O processors
with an overall rate of up to 192 Mbytes/sec are included in
the standard configuration.

\vspace {.1in}
\noindent
{\bf Software:}
\begin{itemize}
\item Uses the NEC standard operating system and UNIX called
      SX-UX is also supported.

\item Does not run the IBM instruction set (unlike other
      Japanese computers)

\end{itemize}

{\bf Languages:}
\begin{itemize}
\item Fortran 77 with automatic vectorization.  Performance
      tuning tools available are VECTORIZER/SX and
     ANALYZER/SX.   The compiler vectorizes IF statements,
     intrinsic functions, and indirect addressing using
     vector gather and scatter instructions (into
     temporaries).

\item Other languages supported (but not vectorized)
     include  ALGOL, PL/I, BASIC, PASCAL, C, LISP, PROLOG,
     and COBOL.
\end{itemize}

\vspace {.1in}
\noindent
{\bf Performance:}
Maximum rating of the SC-JA is 250 Mflops, of the SX-1EA is
330 Mflops, of the SX-1A is 665 Mflops, and of the SX-2A is
1.3 Gflops.  It appears to be the most powerful of the
Japanese supercomputers, and the only one to aggressively
address the scalar bottleneck.

\vspace {.1in}
\noindent
{\bf Status:}
First delivery date in the US was July 1986.  The NEC
machine is available for benchmarking.  NEC has sold 18 of
its supercomputers in Japan, in the USA, and in Europe.
The USA machine is situated at HARC in Houston, Texas.  A
machine was delivered to the Netherlands in 4Q 1987.

\vspace {.1in}
\noindent
{\bf Contact:}

\begin{flushleft}
Mr. S. Adams\\
NEC Information Systems\\
1414 Massachusetts Ave.\\
Boxborough, MA 01719\\
617-264-8800\\

\vspace {.1in}
Garry Foley\\
Manager - Marketing\\
Communications Systems Division\\
NEC Business Systems (Europe) Ltd.\\
NEC House\\
1 Victoria Road\\
London W5 6UL\\
England\\
01-993-8111  Telex 261914 NEC LDN\\

\end{flushleft}

.
