On 22 Dec 1999, Camm Maguire wrote: > Emil Briggs <[EMAIL PROTECTED]> writes:
(And a whole lot of other people wrote) Thanks! That looked like a very, very useful summary. Although the thread will now of course be in the list archives from which it can easily be retrieved (via the www.beowulf.org page) I took the liberty of grabbing the original question and all the responses and putting them "as is" on a text page (links not active, sorry, as I didn't want to mess with html reformatting of the responses). It can be retrieved at: http://www.phy.duke.edu/brahma/blas for anyone who wants a text copy of the whole discussion and all the extremely useful suggestions. If any more come in, I'll try to remember to append them. To summarize my own interpretation of the responses: http://www.netlib.org has lots of LAPACK and BLAS stuff, including sources, for levels 1, 2 and 3 which basically describe vector, vector/matrix, and matrix/matrix transformations. http://www.netlib.org/blas/faq.html is a BLAS FAQ, written (apparently) by Greg Henry, who also provides a non-GPL but still basically free binary link library optimized for the PPro and PII, but not fully optimized for the PIII or Athlon (no prefetch). The ATLAS package: http://www.netlib.org/atlas/ is (according to Emil Briggs of NCSU, <[EMAIL PROTECTED]>, who seems to be something of an expert on this) is "a good solution under Linux". The license isn't quite GPL, but shouldn't obstruct its usage. Emil also has optimized at least level 1 things for the Athlon. The result might be adaptable to the PIII prefetch fairly easily. The result is at: http://nemo.physics.ncsu.edu/~briggs/blas_src_v0.11_tar.gz Camm Maguire <[EMAIL PROTECTED]> pointed out that Debian has an atlas-based package that provides a binary compatibility blas library. He also backed his assertion that atlas is a very good solution with a set of benchmarks on a cluster that showed what appeared to be very reasonable performance scaling (although I'm still trying to figure out just what the benchmarks mean...;-). This would support the assertion that ATLAS works well under linux and can be packaged for distribution without running into licensing issues. Finally, I myself discovered (as was also pointed out by several respondants) that LAPACK/BLAS routines are available via the RPM repository: http://rufus.w3.org/linux/RPM/ In particular, BLAS man pages are available there, which should prove to be invaluable even to those who e.g. use Greg Henry's optimized libraries. To close with a mildly political statement, I'd recommend that in cases where folks have energy to put into LAPACK/BLAS for linux and beowulfery, they should focus on open source solutions (GPL or not) as ATLAS appears to be and avoid the "easy" route of using binary libraries with uncertain licensing. If just a few folks who are interested join Emil in his efforts to optimize for the common processor families it is likely that the libraries will very rapidly become extremely good, while in the case of closed/proprietary libraries (however nice they may be) you are always at the mercy of the owners with respect to bugs and performance both. Remember, a beowulf is a COTS, OPEN SOURCE based cluster supercomputer, at least to the extent possible. rgb Robert G. Brown http://www.phy.duke.edu/~rgb/ Duke University Dept. of Physics, Box 90305 Durham, N.C. 27708-0305 Phone: 1-919-660-2567 Fax: 919-660-2525 email:[EMAIL PROTECTED]
