Sustained and scaling I/O rates
Our sustained IOMeter test hammers drives with 4KB random writes for 30 minutes straight. It uses a queue depth of 32, a setting that should result in higher speeds that saturate each drive's overprovisioned area more quickly. This lengthy—and heavy—workload isn't indicative of typical PC use, but it provides a sense of how the drives react when they're pushed to the brink.
We're reporting IOps rather than response times for these tests. Click the buttons below the graph to switch between SSDs.
The graph of the 860 Pro 1TB's sustained performance looks remarkably similar to that of the 850 EVO 1TB, peaking around 90K IOPS for roughly 200 seconds before dwindling to a constant speed around 8K IOPS.
And that's exactly what's happening. The 860 Pro's peak and steady-state speeds are very similar to those of the 850 drives, both Pro and EVO.
Our final IOMeter test examines performance scaling across a broad range of queue depths. We ramp all the way up to a queue depth of 128. Don't expect AHCI-based drives to scale past 32, though—that's the maximum depth of their native command queues.
For this test, we use a database access pattern comprising 66% reads and 33% writes, all of which are random. The test runs after 30 minutes of continuous random writes that put the drives in a simulated used state. Click the buttons below the graph to switch between the different drives. And note that the P3700 plot uses a much larger scale.
The 860 Pro demonstrates very graceful scaling for a SATA drive, yielding tangible speed gains all the way to a queue depth of 32. Let's take a look at the Samsung crew all together.
The 860 Pro scales strictly better than the 850 EVO and about as well as the 850 Pro. With its PCIe and NVMe advantage, however, the 960 EVO lives in a different dimension.
The 860 Pro has proved itself to be every bit as good in IOMeter as the SATA drives that preceded it. Now it's time to see what kind of numbers it puts up in the real world.