The 2015 Spring Simulation Multiconference will feature the 23rd High Performance Computing Symposium (HPC 2015), devoted to the impact of high performance computing and communications on computer simulations. Advances in multicore and many-core architectures, networking, high end computers, large data stores, and middleware capabilities are ushering in a new era of high performance parallel and distributed simulations. Along with these new capabilities come new challenges in computing and system modeling. The goal of HPC 2015 is to encourage innovation in high performance computing and communication technologies and to promote synergistic advances in modeling methodologies and simulation. It will promote the exchange of ideas and information between universities, industry, and national laboratories about new developments in system modeling, high performance computing and communication, and scientific computing and simulation.