Take a computer with its given speed, stated in MegaHertz or GigaHertz. When the data inside it zips along in 16-lanes of highway, and when it zips along in 32-lanes of highway, obviously the latter gives you faster performance. Most new software are 32-bit. Excitingly, new 64-bit chips are being launched. Several distributions of GnuLinux have a 64-bit version. The only way to find out the version of your software is by checking with the software manufacturer.