The official line is as follows:-
Requirements if using the parallel port for machine control:
Desktop PC (Laptops are not supported) with at least one parallel port
32-bit version of Windows 2000, Windows XP, Windows Vista, or Windows 7 (64-bit versions will not work)
1Ghz CPU
512MB RAM
Non-integrated Video Card with 32MB RAM(Large G-code files, especially 3D files will require a video card with 512MB RAM or higher)
Requirements if using an external motion device for machine control:
An appropriate external motion controller (options can be found on the Plugins page)
Desktop or Laptop with Windows 2000, Windows XP, Windows Vista, Windows 7, or Windows 8 / 10
1Ghz CPU
512MB RAM
Video Card with 32MB RAM(Large G-code files, especially 3D files will require a video card with 512MB RAM or higher)
(My personal preference is to have a dedicated PC running Mach3 under WinXP).
Tweakie.