A1 is a completely rewritten implementation of ARMCI-like one-sided communication, i.e. an alternative runtime system for Global Arrays.

• low-latency/high-bandwidth
• scalability to at least one million processes
• thread-safety
• modular design ala MPICH
• interoperability with MPI
• software quality (readable, documented source code and robust build system)
• productive interaction with vendors

The Blue Gene/P implementation over DCMF was essentially complete when we transitioned away from this project in favor of more adventurous projects like MPI-3 and OSPRI.

Jeff Hammond, Sreeram Potluri and Pavan Balaji worked on this project from 2010 to 2012.