4K Random Read/Write
We precondition the Seagate 600 Pro 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 dark green dots signify IOPS during the test, and the light green dots indicate 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 measurements, 4K random performance is a heavily marketed figure.
The Seagate Pro 600 SSD averages 58,253 IOPS at QD256, placing it between the CloudSpeed 500 and the Samsung SM843.
Garbage collection routines are more pronounced in heavy write workloads. This leads to more variability in performance. The Seagate 600 Pro has the highest average 4K random write speed, coming in at 31,636 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, this is expected behavior. The SM843 has a much tighter latency range, but suffers from significantly lower average write speeds.
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 Seagate 600 Pro proves more resilient to mixed workloads with a tighter performance range than the CloudSpeed 500 as we mix in more write activity. The SM843 again exhibits a nice tight performance range. Unfortunately, this falls in at under half the speed of the Seagate 600 Pro.
The Seagate 600 Pro's great 4K write performance reflects in the latency histogram, with 5,211,437 I/Os (55%) delivered at 4-6ms, 2,719,100 I/Os (28.7%) at 6-8ms, and 1,191,102 I/Os (12.6%) in the 20-40ms 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 Seagate 600 Pro is in the middle of the pack with an average of 3.43 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 Seagate 600 Pro delivers big in the efficiency test, with an average of 9,978 IOPS per Watt during the measurement window.