Thank you very much for your valuable advice. 
My network is made up of some PCs with win7 and only one with win10. I'm
doing these tests in order to switch to win10 with all PCs.
Now I did a test, I placed both data and application on the NAS, and each
PC has its own copy of paradox installed. In my opinion the performance has
improved but I would like your opinion on the configuration I am using. 
So if I understood correctly I would have a marked improvement in performance
using a server with win server on board.
What kind of PC hardware do you recommend? 
Sorry for my bad English , Thanks Fabio