For the most part, if you want to upgrade your data bus, you'll need to get a whole new computer system, since the data bus is an inextricable component of your computer's internal circuitry. When replacing your computer, there are a number of things to keep in mind about the data bus:

Look for systems that use PCI and AGP architecture. The PCI as well as AGP bus are now the acknowledged leaders in the field, providing a 32-bit-width data bus running at 33 megahertz (MHz); this can be expanded to a 64-bit width running at 66 MHz.

Go for "Plug & Play" devices if they're available. This will make installing add-on devices much easier, especially for the home computer user.

SCSI-3 is the latest version of the internal/external, high-speed SCSI bus. However, devices available with this standard are still relatively expensive.