A farm of off-the-shelf microprocessors is evaluated for use as a real-time parallel postprocessing subsystem of the Lawrence Berkeley National Laboratory datapath, including backscatter proximity correction. The native data format is GDSII with embedded control. Data storage is fully hierarchical with no intermediate binary pattern data formats. Benchmarks of a four Pentium pro(TM) farm, after optimization, demonstrate compatibility with exposure rates of 25 MHz for 32% area fill on a vector scan Gaussian beam e-beam tool. Scalability of the architecture is discussed in detail.