The WD Black 2018 NVMe SSD is the company's flagship offering for demanding gamers and enthusiasts. Looking at our averaged real-life performance results, it is the fastest SSD we ever reviewed. The differences to other high-end NVMe drives are small, though—most of these drives are within a few percent of each other. Compared to 2.5 SATA drives, the WD Black is about 15% faster because of its much higher read/write speeds. While theoretical speeds of NVMe drives are generally much higher than their SATA counterparts, real-life differences are small because even with normal SATA drives, disk activity is no longer the main reason for application slowdowns and the bottlenecks shift to other tasks. Even with (theoretically) infinitely fast storage, your applications would not run infinitely fast.
While WD quotes "up to 2,800 MB/s" write speeds, the reality is quite different. Such high speeds will be achieved for only two or three seconds, after which the pseudo-SLC cache is exhausted and the drive has to write to TLC directly. While direct writes are still very fast at around 800 MB/s, I find it a bit questionable to claim enormous "up to" write speeds that will only lead to user disappointment in real life. Of course, WD is not the only company that does so as it seems a rather widespread practice in the storage industry, which is the reason we take a close look at write speeds in our testing.
Thermals of the WD Black are excellent—the drive doesn't throttle at all, not even in worst-case conditions (lots of random writes with no airflow). Part of the reason for that seems to be the small SLC cache, which simply limits effective write speeds a bit, giving the controller some time to cool off. Still, other M.2 drives do much worse here.
At $105 for the tested 500 GB version, the WD Black is reasonably priced; however, some competing drives are cheaper. For example, the ADATA SX8200 and SX8200 Pro are just as fast and cheaper at the same time. Most of these drives don't come with the generous five-year warranty WD is including with their drive. When compared to Samsung's offerings (970 Pro / EVO), there simply is no contest. The WD Black is the better choice, especially when you consider that Samsung's drives are more expensive. The only exception favoring the Samsung 970 Pro would be if you have to move a ton of data around, where the write speeds of the Samsung 970 Pro can make a difference.
Strong competition comes from 2.5" SATA drives for users who are just looking for cheap storage without a priority on performance. Drives like the Mushkin Source are starting to reach the 10 cents per GB mark, and higher performance models like the Crucial MX500 are sitting at around 15 cents per GB, which is significantly more affordable than the 21 cents per GB of the WD Black—if you are willing to take a (small) performance hit for the cost saved.