Not the first time…
Western Digital Caught Bait-and-Switching Customers With Slow SSDs
Guess that was too much to hope for. According to a report from Chinese tech site Expreview, the WD SN550 Blue — which is currently one of the best-reviewed budget SSDs on the market — has undergone a NAND lobotomy. While the new SSD variant performs on-par with the old drive that WD actually sampled for review, once you exhaust the SLC NAND cache, performance craters from 610MB/s (as measured by THG) to 390MB/s (as measured by Expreview). The new drive offers just 64 percent of the performance of the old drive.