Performance of Hardware Compressed Main Memory

A novel memory subsystem called Memory Expansion Technology (MXT) has been built for compressing main memory contents. This allows effectively a memory expansion that presents a “real” memory larger than the physically available memory. This paper provides an overview of the architecture and OS support and in-depth analysis of the performance impact of memory compression using the SPEC2000 benchmarks. Our results show that the hardware compression of memory has a negligible penalty compared to a non-compressed memory. We also show that most applications’ memory contents can be compressed usually by a factor of two to one. We demonstrate this using industry benchmarks, webserver benchmarks, and the contents of popular web sites.