On Jul 29, 2010, at 3:06 PM, Yujie wrote: > Dear PETSc developers, > > When the program based on PETSc runs in parallel mode, how much size > of the matrix can MatLoad load?
Currently the limit is that each individual process cannot hold more then 2 billion nonzeros when using MatLoad(). So if you have more processes you can hold as big a matrix as you want. Within a few days PETSc-dev will eliminate this limit (which comes from how we use MPI). But you need to ./configure PETSc with the option --with-64-bit-indices and need an operating system that supports 64 bit points (which you likely have). > Does the program need to save the whole matrix in one CPU, No, absolutely NOT. Barry > or is each > CPU in charge of the part of the matrix? > > For example, I have one matrix of ~30G. There are two CPUs on each > nodes with totally16G memory. I have 8 nodes. I use 16CPUs for > running. Can I load this matrix using MatLoad? Thanks a lot. > > Regards, > Yujie
