Dear Sayed,
My name is Kristian and I am one of the engineers from Cisco Small Business.
I am afraid that the answer to your question is not straight forward and it depends on many factors such as
-Network load
-Amount of users
-Functionality
-Applications running on the network
As this is a SF switch most of your ports will be 100Mb - you need to consider whether this is appropriate for your network needs.
Regards,
Kris