Sql Azure - separate servers?

Everybody is saying the azure database server is a just a logical concept that don't need to worry about it, but, there are some limitations, in the portal, the server list, it actually tells you the available quota on that server, which means you can not really put too many databases on 1 server, so, we can not really think it of just as a logical concept, otherwise , why there is a limit there. for example, right now you can not put 3 P3 tier database on one server, because the maximum DTUs of one server is only 1600 DTU, and 1 p3 tier database will take 800 DTUs.

So, i can not just think of the azure database server as just a logical concept server to manage the credentials. If there is a limitation there, I guess there will be something somewhere affect the performance in general.

Unless someone can help explain where does that limitation come from.

Actually, with the retired web/business tire, a bad neighborhood could affect your database performance, this made more wondering the server is really just a logical concept?

The physical location of your database and the number of servers have absolutely nothing to do which each other. Wether you have 10 servers and 10 databases or 1 server and 10 databases, it is the same. In the end you will have 10 databases, located physically on various parts of the cloud in a distribution that you absolutely have no control over. They may be all 10 on the same physical host (unlikely), or each one on a separate host (much more likely), you won't be able to control nor will you be able to actually find out.