I have a 120g vertex 2 and I use about 35GB without games installed, pagefile on 8GB, hibernation on 6GB, and the most essential program for works such as photoshop, acrobat, firefox, firewall, antivirus and spyware remover installed. If you disable hibernation and have less ram so that page file is smaller say 4GB or lower/disable pagefile, you will end up using about 21-25GB, so I think 30GB is doable but IMO you are cutting it very thin.