🚀 go-pugleaf

In article <5699@amdahl.UUCP> chuck@amdahl.UUCP (Charles Simmons) writes:
>Seeing how two different people suggested that distributed memory is
>inappropriate for multiple users running independent tasks, maybe someone
>could tell me why.  I find it hard to imagine a problem which is more
>partitionable.  Since the tasks are independent, each user should be very
>happy to have her very own address space.  

This is true only if the machine has a decent I/O architecture, i.e.,
enough paths among local memories and disk(s).  Imagine trying to squeeze
page swaps over multiple inter-node links.  The situation with Intel's
iPSC isn't much better:  a single ethernet linking a single disk with
32 to 128 nodes.  Rumor has it that they're well aware of the problem
and will fix it in the next incarnation.

One visitor to the CS Dept. here described programs and data that took
hours to load and minutes to execute, although that's not exactly what
you're suggesting.

I believe Ncube has a lot of independent I/O paths in their system; does
anyone out there have any experience with their machine?

FPS's T-Series was to have had a disk farm with its own hypercube
connecting the disks and lots of paths up to the processor hypercube.
However the rumor a few months ago on this newsgroup was that
they'd scrapped the project.  Now I hear that John Gustafson (the
designer of the T-Series) doesn't work there any more.  Does
anyone have information on either of these rumors?
-- 
Paul Suhler        suhler@im4u.UTEXAS.EDU	512-474-9517