Results: Enterprise Video Streaming Performance
Video streaming is a 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 page 10 of Intel SSD 910 Review: PCI Express-Based Enterprise Storage.
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.
When we first saw the results of our streaming performance tests, we were shocked. In fact, we performed this test on multiple machines, behind HBAs, on different drives, and with different test software. No matter what we did, we always saw this oscillation.
Even though our overall average was ~430 MB/s, we had some wild swings between 400 and 475 MB/s. The problem with this behavior is that a good portion of the writes are at or below the rated speed of 410 MB/s. How does this translate to sustained performance?
|Threshold||Best-Case Buffer Size||Worst-Case Buffer Size|
|375 MB/s||11 MB||17 MB|
|400 MB/s||23 MB||31 MB|
|410 MB/s||162 MB||172 MB|
|420 MB/s||492 MB||771 MB|
|430 MB/s||1239 MB||1614 MB|
Even though there are prolonged periods of performance well above this drive's specification, the dips below gate the SSD DC S3500's performance. But, even minimal amounts of software buffering should allow you achieve its stated performance. Just don't go much above, or you will pay the price very quickly.