Tham khảo tài liệu 'computational materials engineering episode 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | two dimensions or planes three dimensions of the lattice sites that immediately adjoin its subdomain and which are actually owned by neighboring processors as shown in Figure 3-29 c . The important point is that the processors are all synchronized to update the same flavor of lattice site. The parallel Potts algorithm is shown in Figure 3-30. This algorithm is highly parallel with the only communication cost being the local exchanges of boundary spins between neighboring FIGURE 3-30 The parallel algorithm for the Potts model. 86 COMPUTATIONAL MATERIALS ENGINEERING processors. These exchanges also serve as synchronization points in the loop over flavors to ensure that all processors work on the same flavor at the same time. In practice as long as the processor subdomains are of reasonable size 50 X 50 or larger in two dimensions the communication costs are only a few percent of the total run time and thus the algorithm can simulate large lattices with parallel efficiencies of over 90 WPS 97 . PROBLEM 3-27 Parallel Algorithm Code a 3D square Potts model using a parallel algorithm. Perform normal grain growth simulations for lattice size 200 X 200 X 200 and 107 MCS using 1 2 and 4 processors. Check that identical parabolic kinetics are observed in all cases. Calculate the speed-up per processor of the algorithm. Summary This concludes the investigation of the Potts model speed-up algorithms. The aim of this section has been to give the reader a wide selection of Potts algorithms with which to simulate industrial applications. By the end of this section the reader should have experience with coding boundary-site models n-fold way models and parallel models. We have stressed throughout that it is important to be organized systematic and above all to always verify a new model before applying it to a new phenomenon. Applications of the Potts Model So far we have modeled the general features of grain growth common to all microstructures. However if we are .
