[comp.parallel] Parallel Machines Replacing "Mainframes"

workman@decwrl.dec.com (Will Workman) (02/13/90)

At MasPar, we are focused on fine grain or massively parallel 
computing to leverage Data Parallel programming techniques.  This
approach to leveraging parallelism fits many scientific and 
engineering applications where a grid or array of data can be
assigned to an array of processors with each processor performing
computations for a point or group of points in the array using
a single instruction stream (indirect addressing can provide some
flexibility on the data selected for each processor).  This 
approach generally involves large data sets, and the time to
swap out one user for another is generally excessive, and not
appropriate for "time sharing" as we have known it for extending
the access for large machines.  

Your focus appears to be on course grain or multi-processing
parallelism - and we can expect that mainframes or other
larger machines will continue to evolve with multiple processrs
and newer operating systems like Mach replacing standard UNIX
and single processor configurations.  There is no architectural
boundary that would preserve single CPU systems as most of
the earlier mainframes or time sharing systems were based on.
We expect that the operating systems will continue to evolve
to take advantage of multiprocessor configurations including
load balancing.  But a fundamental difference is that we are
still process driven, and not able to take advantage of the
power of Data Parallel programming techniques that offer the
highest performance on problems with thousands of data points
commonly found in scientific and engineering applications.

My personal viewpoint - is that we must separate parallelism
into two types - multi-processor which is process driven and
Data Parallel - as the trade-offs become clearer and the
programming techniques are distinctly different.

Best Regards > > Will Workman, Dir of Fed Mkt, MasPar