How to Use Multiple Hard Drives

by Paul Sanders
Published September 14, 2010 | Updated June 12, 2015

Using multiple hard drives on a single computer offers a few advantages. More hard drives allow you to store more programs, photos, music, and other data. A second external hard drive or a backup internal hard drive can save your data from being lost if your other hard disk fails. Here are some steps for installing multiple hard drives on the same machine.

Installing Multiple Hard Drives:

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Things You'll Need
Two hard drives or more
Computer
  1. Determine the Setup You Want

    There are two main ways to use multiple hard drives on a single computer:

    Ways to Setup Multiple Hard Drives:

    You can connect multiple external hard drives to a laptop or desktop computer using a USB or Firewire connection. External hard drives are easy to install and are usually portable.

    You can install additional hard disks on a desktop computer. This setup requires that you set up each drive as a separate storage device or connect them with a RAID configuration, a special method for using multiple hard drives. Hard drives in a RAID setup require a motherboard that supports RAID. The hard drives store data in combination or mirror one another to back up duplicate data on multiple hard disks.

  2. Install the Hard Drives

    If you're installing an external hard drive, simply plug it into a USB or Firewire slot. An internal hard drive requires a few more steps. Most desktop computer cases will have spaces for multiple hard drives. It's best to use identical hard drives with the same amount of hard disk space and speed. Any new hard drives will include connector cables to attach to the motherboard and the power supply. You might need an adapter cable if existing power cables don't match up with the ports on your hard drives.

  3. Configure the RAID Utility

    Turn on your computer. During start up, your screen will display which keys you need to press in order to access the RAID utility program (usually "F4" or another function key). From the utility program, you can configure your hard drives into one of the following hard-drive arrays:

    Hard-Drive Arrays:

    RAID 0: This configuration splits information across multiple hard drives in a setup known as "striping," treating them all like one large hard drive. This configuration can speed up your computer's performance.

    RAID 1: This configuration makes one hard drive "mirror" another hard drive, creating an exact copy for back up purposes. RAID 1 has the advantage of safeguarding your data in case one hard drive fails.

    Other RAID configurations: Hard drives can be combined in more advanced setups, and each of them has different benefits and limitations; but they are usually used by very advanced users with larger numbers of hard drives.

  4. Exit the RAID Utility and Reboot

    Once your computer restarts, you can check the directory to see your new hard-drive combination. The two hard drives will display as a single large internal hard drive for your computer, and you can start copying data and installing programs to that drive.