SSD Preconditioning

Overview

SSD preconditioning is the process of writing a solid state drive into a representative steady state before performance testing. It first writes every logical address with valid data — typically via a sequential write — then drives the SSD to a steady state in which the drive's overprovisioning is redistributed across the media in a particular way, the condition under which random-write performance should be measured. The cost of this process has exploded with capacity: on roughly 1TB drives random preconditioning took about 30-45 minutes, but on drives beyond 64TB and 128TB it can now take more than a day or even weeks, making conventional random preconditioning nonviable and slowing development and qualification. This bottleneck is the motivation for SanDisk's Sprandom method.