On Fri, 15 Jul 2016 19:53:31 +0200 "Jose E. Roman" <[email protected]> wrote:
> > The default spectral transformation (STSHIFT) will allocate just one vector. > At which exact point are you seeing that it allocates a bunch of vectors? Yes I think you are right. I can get beyond STSetUp with the right settings. Now the solver runs out of memory inside EPSGetStartVector. > > Is this the unmodified ex3.c? Or did you change anything like > EPSSetOperators(eps,A,B) ? good question. I didn't change much, let me try again the original. > Do you get the same behaviour with the original ex3 with the same problem > size? Yes > > Do you have the same problem with a smaller problem? (half size, say) Halving n gives a quarter of the dimension, which is 8gb vector sizes. It works fine and uses a total of 48gb ram. Oh, I see at one point during initialization it hits a maximum of 56gb. So I guess it needs to keep 6 vectors in total. With the original problem size this becomes 192gb which is just a few gb too much to crunch. I guess I can still try it, but it doesn't feel good hitting the harddrive that much. Thanks for the suggestions. Simon.
