ADVANCED WRITE TESTING
As we talked about in our Micron P400m SSD Review, SSDs have different performance states. Since the Samsung SM843 is an enterprise SSD, we will focus on steady state performance.
With the following tests, we stressed the drive using random 4KB write workloads across the entire span for at least 24 hours. This is more than enough to achieve steady state. The following graph is showing the latency and IOPS across an 11 hour span.
The above graph shows the 1 minute averages over 11 hours. Even though the SM843 is rated for 11.5K IOPS, we consistently observed nearly 13K IOPS across the entire run. We also observed latency at or very near the 2.56ms in the specificaiton.
Even 1 minute averages may not show the true behavior of an SSD. The following graph shows the 1s average across the final hour of our endurance test.
When looking at the results at this level, we can conclude a couple of things. The first is that the data is really tightly packed. At first glance, the distribution of data looks great. The statistics back it up with a standard deviation is only 0.08ms, which is really low.
When we compare the data to the specification, the results aren’t quite as positive. Only ~77% of data points were at or below the rated specification. This is considerably lower than the Micron P400m and the Intel SSD DC S3700. To put it in perspective, for the Micron P400m, 97.5% of writes were at or below its 2ms specification.