I want to use ubuntu 14.04 64bit as a host to run virtual box. Some places say that the minimum ram requirement for ubuntu is 512mb where as on the downloads section it says that 64bit is only for computers with more than 2gb of ram. So I wanted to know what you think the ideal amount of ram I should give to ubuntu (as the host OS)? The OS which I'm running in virtualbox needs as much RAM as possible and I've only got 3.9gb of the stuff, so what do you recommend? I want the virtual machine to run as well as possible, and there will be no other program's running on ubuntu while I'm running the virtual machine.