On Mon, Jun 7, 2010 at 1:56 AM, Dr. David Kirkby <david.kir...@onetel.net> wrote: > ATLAS in Sage is rather old, with there being many more recent beta > releases. > > ATLAS development has not stopped, but I understand from Clint (the main > developer), that he has other commitments which means he will spend less > time on ATLAS for a while. So there are not going to be any new stable > release coming out soon. > > There are a few specific facts. > > * The current version of ATLAS in Sage takes 8.5 hours to build on 't2' as > it has no tuning parameters for the Sun T2+ processors. The latest beta > fixes that and apparently will build in under an hour on 't2'. So an update > should save more than 7.5 hours when building Sage on 't2'. That should > reduce the build time of Sage on 't2' from around 27 hours to 19.5 hours. > * The ATLAS package in Sage has additional tuning parameters for 3 sorts of > processors. I've never managed to work out how to move them to a newer > release, so they might be lost if we changed to a new beta. > * The latest beta has lots of turning parameters for new processors, so > should build more quickly, and probably run faster too on many new > processors. Less CPUs would be classed as a generic 386. I suspect there is > a good chance the 3 processors in Sage would all be in the updated ATLAS > beta, but I don't know for sure. > * The Sage package has quite a few hacks to get around problems. These may > or may not be necessary if ATLAS was updated. Integrating them might be > difficult, and probably difficult to test, as some require hardware/software > combinations that are quite rarely seen. > * I don't know if there are extensive doc tests in Sage for ATLAS, but a > grep of 'atlas' in the ptestlong.log file shows nothing with 'atlas' in the > name, which make me think there might not be. Clearly if we don't test > ATLAS, it is more difficult to know of any problems if an upgrade takes > place. > > I would generally be reluctant to use beta software, but in this case, the > problems with building ATLAS on 't2' are very severe. > > Another option, that would solve the ATLAS problem on 't2' is that the ATLAS > package is expanded with some binaries for such processors. That would add > 1.6 MB to the Sage package. > > I've discussed this with William a bit off-list, and we agree that if a new > ATLAS package is made, it should go in an alpha0, so gets the longest test > duration. We would then have to sort out any problems. > > Thoughts?
I am personally all for updating to the beta version of ATLAS. -- William -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
