The Benchmarker should be able to run multiple SolverBenchmarks in parallel, but probably no more then there are CPU's available.
It should be possibly to specify in the BenchmarkConfig as an absolute number and also relative to the number of CPU's (for example cpuCount - 1).
This is not an alternative to
JBRULES-681 Mult-threaded Solver, nor does that make this obsolete. When you are running multiple Solvers at the same time in production on different problems, it makes sense to bind them to a single or a few threads. Yet it's annoying not to be able to make use of all cpu's during benchmarking.