Black-Box Performance Modeling for Solid-State Drives

Flash-based Solid-State Drives (SSDs) have become a promising alternative to magnetic Hard Disk Drives (HDDs) thanks to the large improvements in performance, power consumption, and shock resistance. An accurate SSD performance model will provide the important research tools for exploring the design space of flash-based storage systems. While many HDD performance models have been developed, architectural differences prevent these models from being effective for SSDs, mostly because their designs cannot accurately account for many unique SSD characteristics (e.g., low latencies, slow updates, and expensive erases). In this paper, we utilize the black-box modeling technique to analyze and evaluate SSD performance, including latency, bandwidth, and throughput. Such an approach is appealing because it requires minimal a priori information about SSDs. We construct and evaluate our models on three commercial SSDs. Although this approach may lead to less accurate predictions for HDDs, we find that a black-box model with a comprehensive set of workload characteristics can achieve the mean relative errors of 20%, 13%, and 6% for latency, bandwidth, and throughput predictions, respectively.