You will notice absolutely no difference between these processors.
You cannot upgrade from a P2 to a P4 and there is very limited potential to upgrade from a P2 to a P3.
P3's went from about 650MHz - 1.4Ghz click here
Samsung Galaxy S8 review
1995-2015: How technology has changed the world in 20 years
What’s happening in VR right now: From psychedelic art to combat therapy
Siri not working? Try these troubleshooting fixes
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.