--Doug
On 10/7/06, Douglas Roberts <[EMAIL PROTECTED]> wrote:
On 10/6/06, [EMAIL PROTECTED] < [EMAIL PROTECTED]> wrote:Quoting Douglas Roberts <[EMAIL PROTECTED]>:
> I disagree about the InfiniBand bit. Myrinet, and now, the newer
> Infiniband technology are commonly used on distributed memory systems.
Systems or applications? What systems? I know Intel sells a version of
Treadmarks that has a DSM server, but what hardware vendor uses Infiniband to
make a unified NUMA memory, e.g. like an Altix?
Lots of systems use Infiniband interconnet technology, but for distributed memory machines, not NUMA.
http://www.osc.edu/press/releases/2004/voltaire.shtml
http://www.beowulf.org/archive/2001-October/005268.html
http://www.linuxdevices.com/news/NS7459807643.html
http://www.hpcwire.com/hpc/506904.html
etc.. There's nothing magic about Infiniband, it's just a faster, lower-latency Myrinet. See below for a note regarding NUMA machines.> The +2GB/sec bandwidth of these interconnect fabrics is important for message
passing applications.
For a NUMA system, where application parallelism isn't limited to message
passing, latency is more important than bandwidth. Message passing as a way to
write programs is what I find constraining!
Distributed applications will probably always scale better than shared memory applications because there are not very many shared memory or NUMA machines out there, and the distributed memory machines are much bigger than any of the shared memory or NUMA machines currently in production. The Altix 3000 is one of the few NUMA machines currenly still running at a few places, and SGI no longer is in business, at least with respect to NUMA machines. NUMA machines, while fun to play on, are really better suited to the hobbyist, since you don't find them (with but a few exceptions) in the production world.
Learning how to design effective message passing distributed applications is not easy, but is is worth it when you have an application that needs to scale.
--Doug
--
Doug Roberts, RTI International
[EMAIL PROTECTED]
[EMAIL PROTECTED]
505-455-7333 - Office
505-670-8195 - Cell
--
Doug Roberts, RTI International
[EMAIL PROTECTED]
[EMAIL PROTECTED]
505-455-7333 - Office
505-670-8195 - Cell
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