You might want to check src/mat/examples/tests/ex109.c for this usage.. Satish On Tue, 24 Apr 2007, Mads Fredrik Skoge Hoel wrote: > Thanks, for clearing that up. Truly helps alot. From an efficiency point > of view I will go with option 2. And maybe implement a third option: to > create an SeqAIJ if run as a uniprocessor program. >