today I learned 1500 CD-ROMs 3.3 quadrillion four-drawer file cabinets Terabyte to Petabyte 20 terabytes terabytes check out this article. 1500 CD-ROMs 10 billion four-drawer file cabinets 2 gigabytes to 1 terabyte 5 GB equates to how many gigabytes are in a terabyte