[Beowulf] Broadcast - not for HPC - or is it?

[Bogdan Costescu]

On Tue, Oct 5, 2010 at 3:40 PM, John Hearns <hearnsj at googlemail.com> wrote:
> However this device might be very interesting if you redefine your
> parallel processing paradigm.

I would say that's always true :-) If you can change the way you do
things, then adapting to the most appropriate hardware/software
combination makes sense to get the maximum of performance. Wait, this
has already happened... and then there was chaos... and then came MPI
;-)

> How about problems where you send out identical datasets to (say) a
> farm of GPUs.

You still need to send point-to-point data forth (what to do with the
bulk data) and back (the results). Then you have the big problem of
synchronizing the 2 channels: the broadcast one and the point-to-point
one. This can come from either GPUs taking different time to finish or
from point-to-point communication delays/congestion. And then the
efficiency brought by broadcast might just go away...

Cheers,
Bogdan