Re: tlug: Karl-Max has cool dreams [was: dual-pentium processors]

["Manuel M. T. Chakravarty" <chak@example.com>]

"Stephen J. Turnbull" <turnbull@example.com> wrote,

> >>>>> "Karl-Max" == Karl-Max Wagner <karlmax@example.com> writes:
> 
>     Karl-Max> By 2020 your computer will house a 64 paralell processor
>     Karl-Max> chip
> 
> The other stuff is one-dimensional extrapolation as far as I can see,
> and (possibly) conservative.  Why do you think this will take so long, 
> and why do you think it will be as few as 64?

The question is, will it help you much?

There are not many people who can write a program that
scales to 64 processors, and if you can, it is an aweful lot
of work.  And then there are more problems where we don't
know any useful parallel algorithm than problems where such
algorithms are know.  Furthermore, there is no compiler
taking your sequential program to a parallel program[1].  I
don't know how many years of worldwide research in parallel
programming and still only very moderate results -- its a
hard nut!

I don't think, there will be ubiquitous parallel computing
without a paradigm shift in programming languages.  Please
don't extrapolate from your two- or four-processor
SMP-machine to anything more than say eight processors.
With 16 it already starts to get nasty and 64 processors are 
a nightmare.

Cheers,

Manuel

[1] Yes, there are parallelising Fortran compilers, but try
    to use one and you'll see that it is not much easier
    than writing a parallel program in the first place (and
    they only work for a small class of numercial algorithms 
    anyway).
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