Unity 5 system requirements

I have to buy a new PC and I’d like to use Unity 5. What are the suggested Unity 5 system requirements for game development? (I know that games system requirements can change)

Im using Unity 5 on Windows Vista.My laptop specifications only little
-2GB Ram
-78.1GB Hard Disk
-ATI Mobility Raedon X1600
-Intel(r) Core ™2 CPU
-T7200 @ 2.00 GHz
unity does not require a big machine to do it.just need a big space.however unity is compitable for all operating system.

Here are the minimum requirement provided by Unity : System Requirements

But you also need to focus your mind on your target platform (iOS, Android, Xbox One, PC, etc…).

If you buy a very powerful machine, don’t forget that most gamers don’t have super powerful computer or devices, so take care of your development and optimisation.
This doesn’t mean that you need to buy a very low budget machine because it will increase your development time.

A gaming machine could be good for game development but you also need to know if you want to use 3D/2D programs.

You need at least 16GB system ram for light map baking with Enlighten
and 100 GB SSD for GI Cache help you alot