[Mpi-forum] MPI One-Sided Communication

[Greg Lindahl]

On Fri, Apr 24, 2009 at 09:10:48PM -0500, Jeff Hammond wrote:

> Frankly, this is just a religious war already waged in HPCWire
> (Myricom versus IBM).  It appears you're saying that IBM and Cray
> supporting powerful one-sided hardware is a waste of money.

No, I wasn't really saying that. I did apparently gore your ox,
though... I didn't realize that a discussion of a high level interface
for MPI was a stalking horse for arguing about the benefits of RDMA.

> Is that
> why their machines, SGI's and those running Infiniband (excellent
> RDMA) compose the first 26 slots on the Top500 list?

I believe that many of those systems spend very little time runing
one-sided code. And that the ability to run one-sided code was
probably not the biggest factor in picking interconnect for them.

I was hoping this discussion would stick to technical things. Market
share is by its very nature not a very technical discussion. The
philosophy of whether RDMA is a good idea is by its very nature not a
very technical discussion.

I will now bow out of this discussion.

-- greg