I append a referee report on your excellent paper C486: Parallel Versions of Stone’s Strongly Implicit (SIP) Algorithm I would be happy to publish your paper if you addressed the changes suggested by the referee. This looks quite possible with modest extensions. Please include a discussion of your changes and their answer to the referees in your resubmittal. I thank you for your interest in Concurrency and Computation: Practice and Experience. Send us other good papers (such as SHPF version)! Please send all communication -- including the resubmission -- electronically if possible using the address fox@csit.fsu.edu If you should need a "real address", please use: Geoffrey Fox Computational Science and Information Technology Florida State University 400 Dirac Science Library Tallahassee Florida 32306-4120 Phone 3152546387 Refereee Report C486: Parallel Versions of Stone’s Strongly Implicit (SIP) Algorithm This is a solid paper that should be published. Two minor points 1) Please explain super linear speed up seen in some red black sizes Why does efficiency vary so drastically with size? 2) Discuss quality of red-black method. Is it -- like in Gauss Seidel as good or better than than original sequential case? Here I mean "good" as measured by quality of solution for a given number of iterations