Message-Id: <36B966E6.F5E27A60@dolphinics.com> Date: Thu, 04 Feb 1999 09:22:46 +0000 From: James Cownie Organization: Dolphin Interconnect Solutions Mime-Version: 1.0 Newsgroups: comp.parallel.pvm,comp.parallel.mpi Subject: Re: Switching HUB for beowulf cluster? References: <78osd7$9ji$1@news.kren.nm.kr> <78piue$lrv$1@pegasus.csx.cam.ac.uk> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Xref: ukc comp.parallel.pvm:7967 comp.parallel.mpi:4584 Nick Maclaren wrote: > > |> 2. How much is the need for 100Mbps bandwidth for a beowulf cluster? > |> Will 10M bps only switching hub be ok for clustering or > |> will 100M bps switching hub lead to better overall performance? > > In terms of latency, there is no difference. In terms of bandwidth, > a lot. As the extra expense of 100M bps is now small, I advise > going for that. The reason for using a switching hub, rather than a simple contention hub is to increase the bi-sectional bandwidth. The latency difference (between teh two hubs) is likely unmeasurable at the MPI level, and the point to point bandwidth will also be the same. However a switching hub will allow many simultaneous communications. This can be very important for the overall performance of your application. -- Jim James Cownie Etnus, Inc. +44 117 9071438 http://www.etnus.com