Although soft microprocessors are widely used in FPGAs, limited work has been performed regarding how to automatically and efficiently generate soft multiprocessors. In this paper, an automated parallel compilation environment for multiple soft processors which incorporates parallel compilation and inter-processor communication structures is described. A total of eight previously-developed parallel processing benchmarks have been automatically mapped to a varying number of synthesized soft microprocessors in commercial FPGAs. The new automated infrastructure allows for an evaluation of area, performance, and power tradeoffs for a range of architectural choices. Experiments show that our softmultiprocessor systems consisting of up to 16 processors can offer up to 5x improvement in application performance against their uniprocessor counterparts.