Adam Martin wrote: > Ok, I have been doing a bit of reading up on Beowulf clusters... and I > am now intrigued as to how good they really are... > > > > 1. Does anybody on the list use / or has used one? > > 2. What kind of jobs have /can be achieved with such a setup? > > 3. Would anyone be interested in setting up a cluster and doing some > experiments? > > > > In particular I am wondering if it would be easy to implement such > jobs as graphical rendering, major database queries etc. >
Lincoln University's Centre for Advanced Computational Solutions (http://www.cfacs.co.nz) has a Beowulf cluster of 9x 1GHz/256MB/20GB Athlon boxes linked by private 100MHz Ethernet. This was set-up by Elizabeth Post ([EMAIL PROTECTED]) and supports her COMP615 course on Parallel Computation in addition to internal research and external contract jobs. I have used this for parallel execution of dairy-farm simulation models (written in Smalltalk!), and the development of parallel algorithms for optimisation of such models is the topic of a current M.App.Comp. project under Elizabeth's supervision. In my "embarassingly parallel" case (the jargon for situations where the same task just needs to be repeated independently so there are no serious issues of synchronisation) the 9-processor cluster achieved a speed-up of x7 - x8 over a single processor. The more general case is much more complicated, and efficient utilisation of the resource requires the programmer to partition tasks in such a way that processors are kept waiting for output from other processors as little as possible. Solutions tend to be very dependent on both the specific task and the configuration of the hardware it is to run on. MPI (Message Passing Interface) is a freely available library (in C and Fortran versions) that handles all the low-level aspects of the inter-processor communication. Two good references to the use of MPI (and parallel programming concepts in general) are: http://ww-unix.mcs.anl.gov/dbpp/ - the text of the book "Designing and Building Parallel Programs" by Ian Foster, and http://foxtrot.ncsa.uiuc.edu:8900/Public/MPE - an interactive tutorial "Introduction to MPI" from the National Centre for Supercomputing Applications, USA. Hope this helps - don't hesitate to contact me directly if you want more detail. Rob ------------------------------------------------------------------------------------------- Robert Sherlock <[EMAIL PROTECTED]> SmartWork Systems Ltd., PO Box 36-515, Christchurch, New Zealand. Ph (+64) 3 355 4194 Fax (+64) 3 355 4199 --------------------------------------------------------------------------------------------
