Samsung 845DC PRO 800GB Enterprise SSD Review

4k Random Read/Write

We precondition the 800GB Samsung 845DC PRO for 17,000 seconds, or nearly five hours, receiving performance reports every second. We plot this data to illustrate the drives' 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 green 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 high-granularity testing and 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 occurs 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. 4k random performance is a heavily marketed figure, and is one of the most sought-after performance specifications.

The Samsung SSDs blow past the competition with 85,463 IOPS for the 800GB model, and 85,334 IOPS for the 400GB 845DC Pro at 256 OIO (Outstanding I/O). The Micron M500DC averages 56,259 IOPS, and the Intel DC S3700 averages 76,301 IOPS. Both Samsung SSDs deliver dominating performance in 100% random read environments.

Our Latency vs IOPS charts compare the amount of performance attained from each solution at specific latency measurements. Many applications have specific latency requirements. These charts present relevant metrics in an easy-to-read manner for readers who are familiar with their applications requirements. The arrays that are lowest and furthest to the right exhibit the most desirable latency characteristics.

The 845DC SSDs lead convincingly with the lowest latencies during 4k random read activity. The results of the 400GB and 800GB models are so close they actually overlap. The 845DCs deliver 85,000 IOPS at .5ms, while the DC S3700 provides 76,000 IOPS, and the M500 DC provides 56,000 IOPS.

Garbage collection routines are more pronounced in heavy write workloads, leading to performance variability.

The 800GB 845DC PRO takes the lead with an average of 52,885 IOPS, and the 400GB trails slightly with an average of 49,996 IOPS at 256 OIO. The DC S3700 provides 13,841 IOPS, and the Micron M500DC comes in second with 39,089 IOPS. The delta between the two 845DC PRO models is nearly 3,000 IOPS - well above the 1,000 IOPS set forth in the product specifications.

The 800 GB 845DC PRO extends the considerable 4k write performance lead for the Samsung drives. A reduction in latency is paired with a healthy increase in IOPS. The Samsung competitors also provide significantly better performance consistency during the measurement window. The 845DC PRO delivers tremendous performance at 1ms, which is well above the competing SSDs.

Our write percentage testing illustrates the varying performance of each solution with mixed workloads. The 100% column to the right is a pure 4k write workload, and 0% represents a pure 4k read workload.

The mixed workload tests reveal an incrementally higher level of performance from the 800GB model, and both Samsung solutions deliver a commanding lead in the mixed 4k workload performance.

We only present mixed workload latency if there are unexpected performance results. The 800GB model, which managed to provide more performance during the measurement windows, actually has slightly higher latency than the 400GB model in some mixtures. These mixtures are not part of the published specifications of the drive, and performance is still much better than competing solutions.

We record power consumption measurements during our precondition run. We calculate the stated average results after the device has settled into steady state during the last five minutes of the test.

The 800GB 845DC PRO features the second lowest power consumption with a 4k write workload at 3.22 watts; the 400GB 845DC PRO weighs in at 3.09 watts, the M500DC averages 4.09 watts, and the DC S3700 averages 3.72 watts during the measurement window. The small difference in power consumption, even with double the packages, highlights the low power consumption of the V-NAND packages.

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 800GB 845DC PRO leads slightly with an average of 16,489 IOPS-per-watt. The 400GB 845DC PRO averages 16,160 IOPS-per-watt, the M500DC averages 9,545 IOPS-per-watt, and the DC S3700 averages 8,930 IOPS-per-watt.