Micron P420m SSD Review: 1.4 TB Of PCI Express-Attached Storage

Test Setup, Benchmarks, And Methodology

The Storage Networking Industry Association (SNIA), a working group made up of SSD, flash, and controller vendors, has a testing procedure that attempts to control as many of the variables inherent to SSDs as possible. SNIA’s Solid State Storage Performance Test Specification (SSS PTS) is a great resource for enterprise SSD testing. The procedure does not define what tests should be run, but rather the way in which they are run. This workflow is broken down into four parts:

1. Purge: Purging puts the drive at a known starting point. For SSDs, this normally means Secure Erase.
2. Workload-Independent Preconditioning: A prescribed workload that is unrelated to the test workload.
3. Workload-Based Preconditioning: The actual test workload (4 KB random, 128 KB sequential, and so on), which pushes the drive towards a steady state.
4. Steady State: The point at which the drive’s performance is no longer changing for the variable being tracked.

These steps are critical when testing SSDs. It’s incredibly easy to not fully condition the drive and still observe out-of-box behavior, which may lead one to think that it’s steady-state. These steps are also important when going between random and sequential writes.

For all performance tests in this review, the SSS PTS was followed to ensure accurate and repeatable results.

All tests employ random data, when available. Micron's P420m does not perform any data compression prior to writing, so there is no difference in performance-based data patterns.