However, a RAID configuration may be used to prevent loss of the media files due to disk failure as well.

In most implementations, a minimum of three disks is required for a complete RAID 5 configuration.

You can also connect hard drives in a RAID configuration, which pairs twin drives for double the space or with mirrored data for additional security.

Why not, they thought, it's got four drives in a RAID 5 configuration.

Four 3.5" bays are certainly enough for a good RAID configuration, however, and professional users can easily see the advantage of more 5.25" bays.

RAID configurations for magnetic disk storage.

The x7200 is also capable of various RAID configurations.

Could that render the RAID configuration useless?

The desktop could also be optionally equipped with twin hard disks in a RAID configuration.

Linux can also create 0, 1, 4, 5, 6 standard RAID configurations using md.