Micron RealSSD P320h Review: A PCIe Drive Capable Of 3.2 GB/s

Test Setup, Benchmarks, And Methodology

The Storage Networking Industry Association (SNIA), a working group made up of SSD, flash, and controller vendors, has produced 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 is incredibly easy to not fully condition the drive and still see fresh-out-of-box behavior and think it is 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 RealSSD P320h does not perform any data compression prior to writing, so there is no difference in performance based on data patterns.

Notes

We did run into a few issues during our time testing the P320h, which were mainly related to the Windows driver we were provided. Initially, the sample that Micron sent to us only had Linux support. The company did a great job getting us a driver for Windows so that we could start our benchmarking, but it wasn't completely finished. Micron was also clear that it did a majority of its validation on servers. Our test bench doesn't use a server chipset, and it runs Windows. Twice during our testing the P320h entered a state where it had to rebuild during POST. We didn't lose any data, but the rebuilds took quite a while.

To make sure our issues were configuration-specific, we ran reboot testing under Linux in a 1U server for two straight days. The machine restarted literally hundreds of times without an issue. And because this issue did not affect performance, for the sake of consistency we finished our testing on our standard test bench.