It appears as if Western Digital is preparing a new flagship Gen4 NVMe solid state drive, the WD Black SN850X. The drive was referenced in a December 10th certification filing with the PCI-SIG. The drive will feature a PCI-Express 4.0 x4 interface, but not much else is known about the drive. We can assume that the “X” in its naming could signify a bump in performance over the current WD Black SN850. This could be achieved from an updated controller, newer generation NAND flash, or better stock cooling.
The filing also mentions a drive called “SN820” which could be a successor to the PC SN810, which the company sells to integrators and OEMs.
[PCI-SIG] Western Digital WD_BLACK SN850X NVMe SSD pic.twitter.com/5Q3fNXx72B
— 遠坂小町 (@KOMACHI_ENSAKA) December 21, 2021