An ebullated bed hydroprocessing system is upgraded using a dual catalyst system that includes a heterogeneous catalyst and dispersed metal sulfide particles to increase rate of production of converted products. The rate of production is achieved by increasing reactor severity, including increasing the operating temperature and at least one of throughput or conversion. The dual catalyst system permits increased reactor severity and provides increased production of converted products without a significant increase in equipment fouling and/or sediment production. In some cases, the rate of production of conversion products can be achieved while decreasing equipment fouling and/or sediment production.