On Thu, Aug 11, 2011 at 02:23, Shitij Bhargava <shitij.cse at gmail.com> wrote:
> On eight CPUs, as it turns out, it will not take as long as I imagined. For > a 9600x9600 matrix, to solve for half the largest eigenvalues, it took about > 300 minutes. Although it would have taken much more time than this for > solving half the smallest eigenvalues (I had to kill it at total time of 600 > minutes). This is still much much longer than the LAPACK method, which takes > (for calculating all the eigenvalues at once) about 90 minutes (at the cost > of much memory, which cant even be distributed -- which is unacceptable. You should try Elemental for distributed-memory dense eigensolvers. http://code.google.com/p/elemental/ > Also, I suppose you probably didnt know that I have to calculate ALL the > eigenvalues). Why do you need all of them? What underlying problem are you solving? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20110811/2ae1e870/attachment.htm>
