4K Random Read/Write
We precondition Intel DC S3500 for 18,000 seconds, or five hours, receiving reports on several parameters of workload performance every second. We then plot this data to illustrate the drives' descent into steady state.
This chart consists of 36,000 data points. This is a dual-axis chart with the IOPS on the left and the latency on the right. The dark blue dots signify IOPS during the test, and the light blue dots are latency measurements during the test period. 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 the point that high-granularity testing can give our readers a good feel for the latency distribution by viewing IOPS at one-second intervals. This should be in mind when viewing our test results below.
We provide histograms for further latency granularity below. This downward slope of performance happens very few times in the lifetime of the device, typically during the first few hours of use, and we present the precondition results only to confirm steady state convergence.
Each QD for every parameter tested includes 300 data points (five minutes of one second reports) to illustrate the degree of performance variability. The line for each QD 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 Intel DC S3500 averages 62,817 IOPS with a 4K random workload at QD256. This places it between the Seagate Pro 600 and the Samsung SM843.
Garbage collection routines are more pronounced in heavy write workloads. This leads to more variability in performance. The Intel DC S3500 exhibits a very tight performance range at the bottom of the chart. The DC S3500 averages roughly the same 4K random write speed as the Samsung SM843 at 11,705 IOPS at QD256.
Both the CloudSpeed 500 and the 600 Pro exhibit significant performance variability, but in the entry-level tier of SSD's aimed at read-centric workloads higher performance is still a desired result.
Our write percentage testing illustrates the varying performance of each solution with mixed workloads. The 100% column to the right is a pure write workload of the 4K file size, and 0% represents a pure 4K read workload.
The Intel DC S3500 provides a very tightly defined range as we mix in more write activity, and while the Seagate 600 Pro and the CloudSpeed 500 exhibit more variability, they provide significantly better speed in heavier write scenarios.
The Intel DC S3500 delivers a very tight latency range in line with its consistent performance. The DC S3500 provides 2,006,218 I/O's (57%) at 20-40ms, and 1,479,527 I/O's (42.3%) in the 10-20ms range.
We record the power consumption measurements during our precondition run. We calculate the stated average results during the last five minutes of the test, after the device has settled into steady state.
The Intel DC S3500 averages 5.08 Watts during the 4K random preconditioning.
IOPS to Watts measurements are generated from data recorded during our precondition run, and the stated average is from the last five minutes of the test.
The DC S3500 offers the lowest Watt per IOP measurement with 4k write activity at 3,065 IOPS. It is important to note that the results are with heavy write activity and SSDs with faster write speeds benefit tremendously. Our mixed read/write workloads will give us a clearer view of the DC S3500 IOPS per Watt in its intended workloads.
It is important to note that the DC S3500 consumed 2.96 Watts in a 4k random read workload. This gives it an IOPS per Watt average of 21,293 IOPS per Watt in a 4K read workload, but among the other competition, this is average.