Analyzing Access Timing of Removable Flash Media

Flash memories could be a basis for mass storage with real-time guarantees if a suitable model for access timing could be established. We describe Flanatoo, a suite of benchmarks which extracts relevant timing information from removable flash media such as compact flash (CF) and USB flash drives. We identified three major timing influence factors: the access block size, the accessed address and (to a lesser degree) the written bit pattern. Despite numerous timing anomalies we argue that removable flash media behave more predictably than hard disks and are indeed a potential basis for real-time mass storage.