An Evaluation of Different Page Allocation Strategies on High-Speed SSDs

Exploiting internal parallelism over hundreds NAND flash memory is becoming a key design issue in high-speed Solid State Disks (SSDs). In this work, we simulated a cycle-accurate SSD platform with twenty four page allocation strategies, geared toward exploiting both systemlevel parallelism and flash-level parallelism with a variety of design parameters. Our extensive experimental analysis reveals that 1) the previously-proposed channel-andway striping based page allocation scheme is not the best from a performance perspective, 2) As opposed to the current perception that system and flash-level concurrency mechanisms are largely orthogonal, flash-level parallelism are interfered by the system-level concurrency mechanism employed, and 3) With most of the current parallel data access methods, internal resources are significantly underutilized. Finally, we present several optimization points to achieve maximum internal parallelism.