On Sun, Jul 10, 2011 at 05:44, John Chludzinski <jchludzinski at gmail.com>wrote:
> 2) Since threads can share data (variables), wouldn't there be less of a > need to send/receive data than using MPI, which simply spawns separate > disjoint processes? > Yes, threads allow more things to be shared, but there is still a problem of data locality and it is often faster to copy than to share. > > 3) " Vec and Mat class"? I hope you're sticking with C (v. C++)? I've > used G++ version 4.3.4 and version 4.5.2 and got different answers with the > exact same source. I have used Visual C++ (2008) and got different answers > than G++ 4.6.1 - again the same source. C99 seems to give consistent > results across compilers/platforms and is simpler to boot. > We generally prefer C to C++, but the symptoms you describe are likely to be caused by writing code with undefined behavior. Unfortunately, there is no checker for undefined behavior, but compiling with -std=c++98 -Wall -Wextra -pedantic does show many things. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20110710/31be1a29/attachment.htm>
