You can't use cublas everywhere because it's better to do small sizes on the CPU and different threads need to be able to operate independently (without multiple devices).
Yes, try a PETSc example before your own code. Did petsc build without any changes to the cholmod interface? ALWAYS send the error message/stack trace---even if we don't have an answer, it usually tells us how difficult the problem is likely to be to fix. On Jun 13, 2012 8:09 AM, "Dave Nystrom" <dnystrom1 at comcast.net> wrote: > Well, I tried it last night but without success. I got a memory corruption > error when I tried running my app. I suppose I should try first to get it > working with a petsc example. I'm building SuiteSparse but only using > cholmod out of that package. Several of the SuiteSparse packages use blas > but cholmod is the only one so far that has the option to use cublas. Tim > gets about a 10x speedup over the single core result when using cublas on > an > example problem that spends a lot of time in blas. So seems worth trying. > Anyway, I think I must be doing something wrong so far. But for the same > problem, Tim gets about a 20+ percent speedup over using multi-threaded > Goto > blas. > > Probably a better solution for petsc would be support for using cublas for > all of the petsc blas needs. Why should just one petsc blas client have > access to cublas? But not sure how much work is involved for that - I see > it > is on the petsc ToDo list. I will try again tonight but would welcome > advice > or experiences from anyone else who has tried the new cholmod. > > Dave > > Jed Brown writes: > > Nope, why don't you try it and send us a patch if you get it working. > > > > On Wed, Jun 13, 2012 at 12:49 AM, Dave Nystrom <dnystrom1 at comcast.net > >wrote: > > > > > Has anyone tried building petsc-dev to use cholmod-2.0 which is part > of > > > SuiteSparse-4.0 with the cholmod support for using cublas enabled? I > am > > > interested in trying the cublas support for cholmod to see how it > compares > > > with mkl and goto for my solves. > > > > > > Thanks, > > > > > > Dave > > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20120613/f27ba3e9/attachment.html>
