Since NVMe helps reduce latency, it shouldn't come as a surprise to see the largest gains coming from random access patterns. Again, Samsung's 1xnm MLC flash is fast enough while reading data to demonstrate the benefit of NVMe. The SM951-NVMe 256GB SSD reaches just over 250,000 IOPS before leveling off. With the same controller and flash, but the older AHCI protocol, the SM951 256GB is down by nearly 100,000 peak random read IOPS.
Of course, peak performance is interesting. But most of us will notice the additional performance at lower queue depths. At QD1, the NVMe model delivers around 2000 more random read IOPS, which is equivalent to a typical SSD product cycle speed-up. Those usually happen each year. But Samsung is delivering a generational upgrade in just a few months.
Comparing the SM951-NVMe to the 850 Pro, we see the equivalent of a two-generation increase at low queue depths. Most users spend 80% of their time reading data and around 20% writing it. Those requests are typically random in nature. Given both stipulations, you're looking at a very large performance boost over the 850 Pro.
We were able to reach Samsung's claimed 300,000 random read IOPS by changing the parameters of our test. In order to do so, we had to mimic enterprise-class benchmarking, veering away from our consumer workloads.