Minecraft is really depends on your CPU. Your CPU is out-dated (sorry to say) and I would recommend getting a new one. As for your friend, what CPU does he have? It also depends on your OS (Windows 8.1 will run games faster than windows 7 and below).
My friend has the intel i5 3570k. And yes, it is the oldest part of my system at the moment. Well. I guess the only option is to buy a new cpu? (Don't worry. I don't mind you saying my cpu is outdated
. I have good other parts which make up for my outdated cpu.)
Again: Any other way than buying a new cpu?
Edit: Im running windows 8.1