4k Random Read/Write
We precondition the Comay BladeDrive E28 for 9,000 seconds, or two and a half hours, receiving performance reports every second. We plot this data to illustrate the descent into steady state.
This dual-axis chart consists of 18,000 data points, with the IOPS on the left and the latency on the right. The red dots signify IOPS, and the grey dots are latency measurements during the test. We place latency data in a logarithmic scale to bring it into comparison range. The lines through the data scatter are the average during the test. This type of testing presents standard deviation and maximum/minimum I/O in a visual manner.
Note that the IOPS and Latency figures are nearly mirror images of each other. This illustrates that high-granularity testing can give our readers a good feel for latency distribution by viewing IOPS at one-second intervals. This should be in mind when viewing our test results below. This downward slope of performance only happens during the first few hours of use, and we present precondition results only to confirm steady state convergence.
Each level tested includes 300 data points (five minutes of one second reports) to illustrate performance variability. The line for each OIO depth represents the average speed reported during the five-minute interval. 4k random speed measurements are an important metric when comparing drive performance as the hardest type of file access for any storage solution to master is small-file random. One of the most sought-after performance specifications, 4k random performance is a heavily marketed figure.
The Comay BladeDrive averages 314,645 IOPS at 256 OIO. The Micron P320h leads with 788,071 IOPS, followed closely by its little brother, the Micron P420m, at 728,111 IOPS at 256 OIO.
The Comay falls short of its specified 520,000 random read IOPS. It is important to note we achieved the rated top speed with FOB (Fresh Out of Box) testing, and with 100 percent compressible data, the SSD scores much higher.
The BladeDrive E28 provides a nearly linear latency scaling as we add in heavier workloads, but at 256 OIO, variability increases. The Micron SSDs offer cleaner latency scaling as the workload increases.
The BladeDrive E28 provides an average of 205,105 IOPS at 256 OIO. The P420m provides an average of 108,342 and the P320h delivers an average of 205,376 IOPS.
The P320h features SLC NAND, so comparisons aren't entirely apples to apples. The E28 delivers an impressive average, and though it experiences variability, it is well above the P420m in performance in this test. The BladeDrive is spec'd at 440,000 IOPS, and with varying levels of compressibility, its peaks are much higher than this 50 percent compressible workload.
The BladeDrive E28 encounters significant variability with the 4k random workload. The P420m and BladeDrive E28 experience variability in this heavy write workload, while the P320h stays steady, a benefit of its SLC NAND. The BladeDrive wins this test in the MLC segment.
Our write percentage testing illustrates the varying performance of each solution with mixed workloads. The 100 percent column to the right is a pure 4k write workload, and 0 percent represents a pure 4k read workload.
The BladeDrive exhibits a nice middle region in performance, and it provides solid performance with write-centric workloads in this test.