Newsgroups: comp.parallel.mpi From: paul@cee.hw.ac.uk (Paul Bristow) Subject: Re: Speed using MPI Message-Id: Sender: news@cee.hw.ac.uk (News Administrator) Organization: Dept of Computing & Electrical Engineering, Heriot-Watt University, Scotland References: <6u64r3$9a5$1@news1.tc.umn.edu> <6u6stn$5mq@news1.newsguy.com> <6u8n37$pek$1@news1.tc.umn.edu> Date: Mon, 28 Sep 1998 15:43:21 GMT AJ Lewis (lewi0235@umn.edu) wrote: : Thanks to everyone who responded to my question. The answers I got back are : very helpful in evaluating the use of MPI for the project I am working on. : I have another question for you now: Is there any way to specify the packet : size in MPI? I know with sockets you can specify a packet size up to a : certain value around 15-16kb. Is there any way to do this with MPI, or does : MPI optimize the packet size for you? : Thanks, : AJ Lewis You probably can modify the packet size but it'll almost certainly be an implementation specific parameter rather than an MPI option. When you were doing your bandwidth tests did you try any other implementations of MPI e.g. lam? -- Paul C Bristow, Dept. Computing & Elec. Eng. Heriot-Watt University, Edinburgh EH14 4AS. Phone: (+44) 131 451 5111 ext 4179. e-mail: paul@cee.hw.ac.uk "The day Microsoft makes something that doesn't suck is probably the day they start making vacuum cleaners" - Ernst Jan Plugge