About Raid; Raid For Performance - Gateway GM5260 Hardware Reference Manual

CHAPTER 4: Configuring Drives for RAID

About RAID

RAID for performance

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RAID (Redundant Array of Inexpensive/Independent Disks) lets your computer use
multiple hard drives more efficiently. Your computer supports RAID 0, RAID 1,
RAID 5, and RAID 10.
RAID 0 lets your computer see multiple hard drives as a single drive. This type
of RAID can increase file access speeds, which is important if you work with
video editing, sound editing, and high-performance games. RAID 0 is also an
affordable way to increase your total file storage capacity.
How it increases performance
The more drives you have in your RAID 0 array, the faster the potential drive
reading performance. All hard drives have limitations on how fast they can read
and write files. If half a file is stored on one RAID 0 drive and the other half on
another RAID 0 drive, each drive only has to read half of the file. So, the entire
file is accessed by the computer up to twice as fast (using a two-drive RAID 0
array). In a three-drive RAID 0 array, if the file is evenly distributed among the
drives, each drive must read only a third of the file, and so on. If the entire file
happens to be stored on only one of the drives, the file is accessed at the same
speed as if it were on a standard hard drive setup. Dividing up files between
multiple hard drives like this is called striping.
How it makes file storage cheaper
Because RAID 0 lets your computer see multiple hard drives as a single drive,
you can install several lower capacity (less expensive) drives and have the same
single-drive storage simplicity and capacity as a larger, more expensive hard
drive.
Drawbacks
Unfortunately, RAID 0 lets multiple drives behave as one in another way. If part
of the array fails (such as a hard drive crashing), the entire array fails. Because
the drives are treated like a single drive, parts of files (including operating
system files) can be spread across several drives, leaving the computer with only
file fragments if one drive fails. Also, because it is more likely that a hard drive
can fail in a multiple-drive RAID setup, regular and frequent backups are critical.
Another drawback is that RAID 0 treats each hard drive as if it has the storage
capacity of the smallest drive in the array. So if you have three drives (300 GB,
250 GB, and 200 GB) in a RAID 0 array, your computer only recognizes 600 GB
total capacity.
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