RE: Distributive Computing

From: "Sale, Mark" <ms93267@GlaxoWellcome.com> Subject: RE: Distributive Computing Date: Thu, 11 Oct 2001 11:22:02 -0400 Getting back to the original question. I think that Mark orginally ask about distributed computing in NONMEM, and I got the impression he meant parallel processing or something like virtual parallel processing. About 6 years ago I worked with SGI to run NONMEM on a 4 processor machine using the compiler they claimed was the best at parallelizing (aka unrolling) fortran code. NONMEM did absolutely no parallel processing, ran entirely on one processor. So, old-fashioned multi processing doesn't work with the existing code. Darin correclty points out that NONMEM also will not multithread. Multithreading requires dedicated coding, and NONMEM is written as a single thread application. I heard a rumor at one time though that Steve Shafer had rewritten some parts of PREDPP as multithread. Multithreading is in principle entirely possible in mixed effect modeling. A number of groups at working on new applications of mixed effect modeling (not yet available) that support multi threading, but don't hold your breath. Mark