Quantum Chemical Calculations on MIMD Type Computers

MIMD parallel computers can be a promising alternative in those cases where application software exploits only a small portion of the maximum performance of vector computers. We compare MIMD systems with other parallel architectures and stress transputer networks pointing out the benefits of this concept. Two different software environments are discussed, MultiTool, a modified transputer development system (TDS) and the distributed operating system Helios. Both are used to implement direct SCF programs on a transputer network. Parallel processing is defined according to the farming concept, both on the program and on the subroutine level. In transputer networks with up to 17 nodes, a very good load balance could be achieved, demonstrating the good suitability of the MIMD-concept for SCF calculations.