By subdividing the object with the tessellate tool, you can operate in your own way. So it provide extra smoothness on curved surface for renderings.
Step1: create a box.
Fig.133
Step2: convert box to editable mesh. So, right click on an object.
Fig.134
Step3: click on polygon option and select a face.
Fig.135
Step4: after that, click on modify tab and select tessellate tool.
Fig.136
Step5: specify parameters then click on update button.
Fig.137