Newsgroups: comp.parallel.mpi,comp.parallel.pvm
From: romero@convex.com (Paco Romero)
Subject: Re: Memory Channel: Message Passing Latency 5.8 usecs, ~60 MB/sec @ 4KB messages
Organization: Hewlett Packard - Convex Division, Richardson, Tx USA
Date: 13 Aug 1996 22:03:49 -0500
Message-ID: <4urfml$cnr@bach.convex.com>

In article <01bb8966$3b025a20$c4400410@richard.pa.dec.com>,
Richard Kaufmann <richard@ilo.dec.com> wrote:
>Rick Gillett and I will be presenting a paper at Hot Interconnects IV
>announcing our results for Digital's HPF, PVM and MPI efforts on Memory
>Channel.  The bottom line is that Memory Channel has achieved 5.8 usecs
>one-way latency for HPF, 6.9 usecs for MPI and 8.0 usecs for PVM.  Achieved
>"ping pong" bandwidth is >60 MB/sec for both HPF and MPI.
>
>We believe this is the first instance of sub-10 microsecond MPI, PVM or HPF
>messaging.
>

Nice job, guys!  I am afraid that you didn't get there first, though :-)
The HP PVM and MPI implementations on the HP/Convex Exemplar SPP1200 achieved
a 5 usec latency back in 1995.  With additional tuning we  achieve an 
impressive 3.99 usec latency and 135 MB/s bandwidth on the SPP1600, and we 
expect the bandwidth to increase significantly with the PA8000 family of HP 
Exemplar servers.  We used Dongarra's ping-pong code available from netlib 
for these measurements.

The HP MPI Web page will be available from the HP/Convex Division shortly
with more details.

Best regards

Paco Romero (paco@rsn.hp.com)
HP Explicit Parallel Models, Project Manager.
HP Convex Division, Richardson, TX. 


>A preliminary version of the paper is available from our HPC InfoCenter
>page at http://www.digital.com/info/hpc/ref/refdoc.html.
>
>Regards,
>
>Richard Kaufmann, richard@ilo.dec.com
>Digital Equipment Corporation
>Galway, Ireland
>
>p.s. MEMORY CHANNEL is a trademark of Encore Computer.  All latency numbers
>are measured by dividing the round trip time by two. 
>
>



