Semi-related question: Why is that? I've been looking for resources on why AMD is a non-starter, but most searches just turn up comparisons for low-level consumers.
AFAIK, it’s the ecosystem and availability. Let’s say you’re a Dell shop and you’re using mostly PowerEdge R730s (one of their middle-of-the-road 2-socket options). Your choice right now is Xeon E5-2600 v4 family, because that’s what that platform supports. These aren’t motherboards that you just pick up at Fry’s, they’re designed as an entire system, which takes a while to get going. Dell is not going to invest the R&D money unless they have demand, but there won’t be much demand without stories of success in the field, so we’re at a bit of a chicken and egg problem right now.
Speaking of Dell, they are launching some EPYC stuff: https://blog.dellemc.com/en-us/poweredge-servers-amd-epyc-pr...
But again, getting the ball rolling might take a couple of years. Look at what happened with Opteron as an example.