In our throughput tests, the reads peaked at 266MB/s (8MB block) before falling back to finish the test run at 205.06MB/s. Writes peaked further back in the test run at the 512KB block mark at 265MB/s, confirming the official figure, before dropping back to finish the test run at 252.94MB/s.
The 22TB Red Pro's peak read result of 266MB/s confirms the official rating of 265MB/s before it starts to fall back against its competitors.
The WD Red Pro's performance appears to be a good deal more consistent than the reads.