The OWC Accelsior 4M2 PCIe SSD has 4 slots for M.2 NVMe SSD modules. It is shipped with SoftRAID to combine those 4 modules into a single volume.
As tested here, it was configured as a single RAID-0 stripe volume. It is also possible to configure it as 4 individual volumes (one per blade), or dual 2-blade volumes, or a RAID-4, and a variety of other possibilities, all courtesy of SoftRAID. Super fast and easy no matter what.
In the MPG review of the 2019 Mac Pro:
Fastest SSD that MPG has ever tested, by far. And it is fanless and thus silent.