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

Enterprise Video Streaming Performance

Enterprise video streaming is becoming a much more demanding workload within the enterprise space. Companies want more HD streams with higher bit-rates and no stuttering. A storage solution well-suited for enterprise-class video delivery has completely different capabilities than something designed for databases. At the end of the day, you're basically looking for exceptional large-block sequential write performance. You also need a high level of consistency that traditionally isn't seen from consumer SSDs. For a more in-depth analysis, take a look at our Intel SSD 910 review.

As a refresher, once the drive is in a steady state, we write its entire capacity 100 times. We use 8 MB transfer sizes and a queue depth of four, recording timestamps for each individual write. The graph below reflects 100-point averaging so that you can better visualize the results.

Frankly, we were shocked after our first look at the data. So much so, in fact, that instead of our usual 100 full writes, we went all the way up to 250. That's over 160 TB of data written to the P320h, including over 20 million individual 8 MB writes. The graph below shows the best- and worst-case runs out of those 250 iterations.

And that's it. Two minor hiccups, each of which is easy to overcome with a modest buffer. Because we are testing the P320h as a formatted drive, just as you would use it in the real-world, it's impossible to even say what caused those dips. They could have very well been from the driver or operating system doing some periodic check on the hardware. The table below shows how much memory would be required to maintain a given threshold.

Threshold (MB/s)Best-Case Buffer Size In MBWorst-Case Buffer Size In MB

These are not normal results, particularly for an SSD. Typically, solid-state storage has issues where, in a very small percentage of writes, the operation takes an order of magnitude longer to complete. This is normally attributed to internal SSD tasks like garbage collection. Because those background operations are inherent and unavoidable, this sort of testing is necessary to measure how the outliers negatively affect streaming performance.

The P320h is such a consistent performer, though, that it needs almost no buffer up to and beyond its rated performance. Normally, when you go beyond the average, the required buffer grows exponentially. But the P320h goes from almost no buffer at 2,000 MB/s, to an unrealistically-high number just 25 MB/s higher.

Based on our maximum latency performance test, these results probably shouldn't come as a shock. But the fact that the consistency held up over such a long period of time certainly surprised us.