6.5 PVM Scaling

PVM jobs involve a certain of network traffic, especially sending multi-conformer molecules from the slaves back to the master. Omega slave jobs are relatively fast compared to the network I/O time, so for scaling beyond 32 CPUs, additional effort is required in setting up a job. For low numbers of CPUs or for divide-and-conquer style applications, using .oeb.gz as the output file format is fine.

As of version 2.0, Omega can write rotor-offset-compressed OEB files (via the -roc command-line flag) that greatly reduce the I/O on the master and allow downstream applications such as ROCS and Fred to scale to larger number of CPUs.