By the late 1980s, several highly parallel systems were able to achieve
high levels of performance-the Connection Machine Model CM-2, the
Intel iPSC/860, the nCUBE-2, and, early in the decade of the '90s, the
Intel Touchstone Delta System. The peak speeds of these systems are
quite high and, at least for some applications, the speeds achieved are
also high, exceeding those achieved on vector supercomputers. The
fastest CRAY system until 1992 was a CRAY Y-MP with eight processors, a
peak speed of 
, and a maximum speed observed for
applications of 
. In contrast, the Connection Machine
Model CM-2 and the Intel Delta have achieved over 
for
some real applications [Brickner:89b], [Messina:92a],
[Mihaly:92a;92b]. There are
some new Japanese vector supercomputers with a small number of
processors (but a large number of instruction pipelines) that have peak
speeds of over 
.
Finally, the vector computers continued to become faster and to have
more processors. For example, the CRAY Y-MP C-90 that
was introduced in 1992 has sixteen processors and a peak speed of 
.
By 1992, parallel computers were substantially faster. As was noted
above, the Intel Paragon has a peak speed of 
. The CM-5,
an MIMD computer introduced by Thinking Machines Corporation in 1992
has a maximum configuration of 16K processors, each with a peak speed
of 
. The largest system at this writing is a 1024-node
configuration in use at Los Alamos National Laboratory.
New introductions continue with Fall, 1992 seeing Fujitsu (Japan) and Meiko (U. K.) introducing distributed-memory parallel machines with a high-performance node featuring a vector unit using, in each case, a different VLSI implementation of the node of Fujitsu's high-end vector supercomputer. 1993 saw major Cray and Convex systems built around Digital and HP RISC microprocessor nodes.
Recently, there has been an interesting new architecture with a
distributed-memory design supported by special hardware to build an
appearance of shared memory to the user. The goal
is to continue the cost effectiveness of distributed memory with the
programmability of a shared-memory architecture. There are two major
university projects: DASH at Stanford [Hennessy:93a],
[Lenoski:89a] and Alewife [Agarwal:91a] at MIT. The first
commercial machine, the Kendall Square KSR-1, was
delivered to customers in Fall, 1991. A high-performance ring supports
the apparent shared memory, which is essentially a distributed dynamic
cache. The ring can be scaled up to 32 nodes that can be joined
hierarchically to a full-size, 1024-node system that could have a
performance of approximately 
. Burton Smith, the
architect of the pioneering Denelcor HEP-1, has formed Teracomputer,
whose machine has a virtual shared memory and other innovative
features. The direction of parallel computing research could be
profoundly affected if this architecture proves successful.
In summary, the 1980s saw an incredible level of activity in parallel computing, much greater than most people would have predicted. Even those projects that in a sense failed-that is, that were not commercially successful or, in the case of research projects, failed to produce an interesting prototype in a timely fashion-were nonetheless useful in that they exposed many people to parallel computing at universities, computer vendors, and (as outlined in Chapter 19) commercial companies such as Xerox, DuPont, General Motors, United Technologies, and aerospace and oil companies.