A separate hard drive: Mac OS X needs its own hard drive (a minimum of 10 GB of space is required, but at least 50 GB of space is recommended). If your computer already has OS X Mountain Lion installed, Unibeast will just update Mountain Lion to Mavericks normally, without deleting any of your apps or files. The hardware requirements for OS X Mavericks are identical to those for OS X Mountain Lion AMD processors and older 32-bit Intel processors (such as Pentium M) are not supported. Be sure to read the Hackintosh compatibility guide (which I will post soon) very carefully, to check whether or not your computer qualifies.
A compatible computer: Not every computer will work with Mac OS X, even with the help of tools like Unibeast and Multibeast.