Its running, so it is "supported" but most likely we have a bug in the reporting of the details on it. Go ahead and file a ticket on https://jira.ixsystems.com with a debug attached (System -> Advanced -> Save Debug) and we can take a look into it.
It's probably due to the fact that it uses AMD's Bulldozer/Piledriver/Steamroller architecture. What they call 2 "cores" is actually a single module with 2 CMT threads on the module.