Blackcomb2: Hardware-Software Co-design for Nonvolatile Memory in Exascale Systems

Memory, not processing, is the crux of the exascale co-design problem. Exascale machines will push the limits of memory capacity, power, and performance. DRAM, the universal memory technology of today, may not scale to meet the needs of exascale. Disk storage, critical for checkpointing and for archiving computational inputs and results, may also fail to provide adequate performance, reliability, and power efficiency. We confront a memory/storage crisis. The Blackcomb effort seeks to create and understand new memory technologies, develop their roles in exascale systems, adapt applications to them, and assess their relative merits. We focus on emerging nonvolative memory (NVM) technologies, including spin-torque-transfer RAM (STTRAM), phase-change RAM (PC-RAM), and memristor (resistive RAM, or R-RAM).