System-level impacts of persistent main memory using a search engine

Computer memory systems traditionally use distinct technologies for different hierarchy levels, typically volatile, high speed, high cost/byte solid state memory for caches and main memory (SRAM and DRAM), and non-volatile, low speed, low cost/byte technologies (magnetic disks and flash) for secondary storage. Currently, non-volatile memory (NVM) technologies are emerging and may substantially change the landscape of memory systems. In this work we assess system-level latency and energy impacts of a computer with persistent main memory using PCRAM and Memristor, comparing the development and execution of a search engine application implementing both a traditional file-based approach and a memory persistence approach (Mnemosyne). Our observations show that using memory persistence on top of NVM main memory, instead of a file-based approach on top DRAM/Disk, produces less than half lines of code, is more than 4× faster to develop, consumes 33× less memory energy, and executes search tasks up to 33× faster.