4K Random Read/Write
We precondition the Kingston SSDNow E100 with 50% compressible data 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. Please refer to the previous page for a note on data compressibility.
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 black dots signify IOPS during the test, and the brown 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 Kingston SSDNow E100 averages 58,934 IOPS with a 4K random workload at QD256. This places it squarely between the Micron P400m and the Intel DC S3700.
Garbage collection routines are more pronounced in heavy write workloads. This leads to more variability in performance. The SSDNow E100 has a wide performance variance, with operations occurring from above 50,000 IOPS to below 5,000 IOPS. This is due to the compression engine working furiously to compress the data as much as possible in the background. We are using 50% compressible data in all of our tests, and more compressible workloads experience significantly less variability.
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 E100 provides a wide swath of performance across the varying workloads, with its peak performance measuring 60,000 IOPS with pure read data. The P400m does fall slightly lower in the 10-90% write testing.
The Kingston E100 has 4,522,717 I/Os (48.0%) fall into the 4-6ms range, and 4,033,748 I/Os (42.8%) 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 Kingston E100's power consumption during this test closely matches the Intel DC S3700. The Kingston E100 consumes an average of 4.5 Watts during the measurement window.
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 Kingston E100's write performance variability leads to a scattered performance range that runs behind the other SSD's in the test pool. The Kingston E100 averages 7,117 IOPS per Watt, the P400m comes in very close with 7,624 IOPS per Watt, the Intel scores 8,336 IOPS per Watt and the Optimus scores 6,617 IOPS per Watt.