Hi, The X4012 should work. I do not see anything that would prevent it from meeting the S2D requirements. 
Simple Question: Which Dell switches are supported for a Storage Spaces Direct deployment: I am looking for a basic solution, so I do not plan on doing RDMA. RDMA is not required by Windows 2016 S2D according to this Claus Jorgensen blog: [URL] Quote: "I often get the question “Is RDMA required for Storage Spaces Direct”. The answer to this question is: no.". I understand that 10Gb IS a requirement of S2D. But are there others? More specifically: Will an X4012 (or two for fault tolerance) work for a 2-node S2D cluster?
Supported switches for Storage Spaces Direct