The Express vSAN Architecture is a single-tier model that takes advantage of the adoption of high-performance NVMe drives and the continuous increase in CPU cores to support a data store based on a single pool of storage instead of disk groups.
With this architecture, every drive can serve both cache and capacity requirements.
During the inventory process, VxRail queries the drive slots and verifies whether a datastore can be built with the Express vSAN Architecture. The data store will only be built with this architecture if all the drive slots contain compatible NVMe drives. If you select this vSAN architecture option, the network that is configured to support the data store must be running at either 10 GbE, 25 GbE, or 100 GbE.