Recently I bought My Book 8TB (New) and it shows strange perfomance using on mac (OS X Sierra 10.12.5) using native filesystem (Mac OS Extended (Journaled)).
Everything OK except Sequential Queue and Random Queue tests with Depth = 32. I use AmorphousDiskMark for monitoring.
On this screenshot you can see bad write perfomance in sequence mode and bad read perfomance in both modes (most reviews shows at leas 1.5mb\sec for 4K).
I test this drive on Windows 10 using exFat filesystem and get normal results, but something wrong on Mac. I have other drive it’s My Book 6TB and there’s no such issues.
Probably there’s compatibility problem on mac using last firmware uses not optimized queues and buffer instructions.