striped RAID set
When you have more than one disk, you can create a Striped Redundant Array of Independent Disks, or striped RAID set, for faster disk access. A striped RAID set is especially useful for large files, such as digital video and database files.
A striped RAID set works best if the disks are about the same size and are connected to your computer via fast connections. Consider the following:
If the disks are different sizes, a striped RAID set treats all the disks as though they are as large as the smallest one. If you have disks of different sizes, you might want to use a concatenated disk set, which doesn’t give you the speed advantage of a striped RAID set, but lets you use the full capacity of all its disks.
If the disks are connected to the computer with slow connections, such as USB connections, you might not get faster disk access, even with a striped RAID set. For best results, use disks with fast connections, such as internal disks.