One-line patch to enable OpenMP in ParallelSampler::update() for-loop.
You need to enable OpenMP (-fopenmp for GCC C/F77/C++) for this to work.
Don't know the internals of JAGS, maybe this is too naive and JAGS samplers could not be threaded.
But at least it fully loads all CPUs in my case.
In theory there should be virtually no trade-offs in parallelizing chains, in contrast to matrix operations.