With every Queue you create in optio you have to connect a port. This port acts as a physical 'printer'. When you connenct multiple queus to the same port, the spoolfiles will wait until the previous one is done.
As these ports can be created with the Control panel tool, this is rather easy to do and comes with little cost.
Keep in mind that every port has te potential to run its own eCI server application, and running 3 eCI programs in the same timeframe on one server can be quite heavy on resources.
