sql-server - services - sql server windows authentication not working
Analysis Services Only Windows Authentication (3)
Actually needing "Active Directory" isn't really true.
You can trick OS's by logging into your PC in any domain with the same User and Password as the account on the other server that's running SSAS. I do it all the time. By default you'll get access if the domains are different but the user/pass is exact.
Is it true that Analysis Services ONLY supports windows authentication?
Dependent on what you're trying to achieve, you can connect via HTTP and IIS, with IIS supplying or passing through credentials: