Yes, it is supported.
The only deployment setup that is not supported, is when you install CRM on a AD domain controller.
If you don't have many users that will use CRM, you can sure install it on a single server (if necessary, you can always migrate to a Multi-server deployment in the future).
I have installed CRM on 1 server (SQL & CRM) with 12GB RAM.
There are +- 30 active users, and CRM is not working slow.
Alexander