Storage-Class Memory: The Next Storage System Technology
Maintaining the performance growth rate of the 30-yearold system memory and storage hierarchy, primarily based on DRAM (Dynamic RAM) and disks, has become a major challenge in the design of large-scale, high-performance computer systems. This challenge manifests itself in many ways. For example, the gap between the performance (measured as latency) of disks and the rest of the system - which is already five orders of magnitude - continues to widen rapidly. In addition, the energy consumption, space usage, and cost of the memory and storage hierarchy are major obstacles to the development of exascale systems capable of 10 18 operations per second.