[Beowulf] Has anyone actually seen/used a cell system?

Andrew Shewmaker agshew at gmail.com
Mon Oct 2 20:21:59 PDT 2006

On 10/2/06, Vincent Diepeveen <diep at xs4all.nl> wrote:
> ----- Original Message -----
> From: "Andrew Shewmaker" <agshew at gmail.com>
> > Saying Sequoia is unusable is like saying that MPI is unusable.
> Let me quote the paper:
> "we present sequoia, a programming language designed to .... "
> So now you withdraw the claim that it is a programming language on its own?

Sequoia, like MPI, is about communication, and you'll have
to write a computational kernel whichever you use.

I'll quote the sentence after the one you point out.

"Sequoia abstractly exposes hierarchical memory in the
programming model and provides language mechanisms
to describe communication vertically through the machine
and to localize computation to particular memory locations
within it."

> Either claim it is an ANL, another new (programming) language,
> or claim it is a library.
> Don't claim both.
> If it is a library which i can call *from* C code, such as CILK, then it
> isn't a programming language, but i can use the efficiency of C code.

But Cilk does claim to be a programming language.  And is Fortran
not a language simply because you can call Fortran from C?

> Of course an ANL is going to fail anyway if you want to be utmost
> compatible, claiming something you created is so compatible that it works
> both for a CELL as well as for a cluster.

Sequoia, like MPI, allows you to write a program that runs on an
SMP or a cluster.  However, MPI would probably be too heavyweight
for a Cell's SPUs.  That's why Sequoia uses DMA directly.  With
either MPI or Sequoia, a computational kernel written in probably
C or Fortran will be crunching as fast as it can over the data that the
communication system gives it.

Andrew Shewmaker

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