If you’re reading consumer SSD reviews and using them to estimate SSD performance under database workloads, you’d better stop. Databases are not your typical consumer applications and they do not use IO in the same way.
Let’s look, for example, at this excellent AnandTech review of Samsung 960 Pro – a consumer NVMe device that I happen to have in my test lab.
The summary table is actually great, showing the performance both at Queue Depth 1 (single threaded) as well as Queue Depth 32 – a pretty heavy concurrent load.
Even at QD1 we see 50K (4K) writes per second, which should be enough for pretty serious database workloads.
In reality, though, you might be in for some disappointing surprises. While “normal” buffered IO is indeed quite fast, this drive really hates fsync() calls, with a single thread …[Read more]