Nvidia NFORCE 650I - Manual (Page 33)

Mainboard nForce 650i Ultra
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Appendix II: RAID Setup
Introduction to RAID
RAID (Redundant Array of Independent Disks) technology is a sophisticated disk
management system that manages multiple disk drives. It enhances I/O performance and
provides redundancy in order to prevent the loss of data in case of individual disk failure. The
RAID facility on this board provides RAID 0, RAID 1, RAID 0+1, RAID JBOD, and RAID 5.
Disk Striping (RAID 0)
Striping is a performance-oriented, non-redundant disk storage technology. With RAID striping,
multiple disks are used to form a larger virtual disk. Data is then striped or mapped across all
the physical disks. In this way, multiple I/O operations can be executed in parallel, enhancing
performance. Striping does not provide fault tolerance. The minimum number of hard drives
for RAID 0 is 2.
Disk Mirroring (RAID 1)
With Disk Mirroring there are redundant disks that mirror the primary disks. Data that is written
to the primary disks are also written to the redundant disks. This redundancy provides fault
tolerant protection from a single disk failure. If a read/write failure occurs on one drive, the
system can still read and write data using the other drive. The minimum number of drives for a
RAID 1 configuration is 2. You are required to use an even number of drives.
Disk Striped Mirroring (RAID 0+1)
This mode combines both the performance benefits of RAID 0 with the fault tolerance of RAID
1. The minimum number of drives for RAID 0+1 configuration is 4 drives. This configuration
also requires an even number of drives.
Note: All mirrored configurations or striped/mirrored configurations should use drives of the
same size.
RAID SPAN (RAID JBOD)
RAID SPAN allows JBOD (Just a Bunch Of Disks) configurations which simply uses multiple
disks to form a larger virtual disk without any other specialized disk management functionality.
RAID SPAN is not considered a standard RAID implementation.
Disk Rotating Parity Array (RAID 5)
RAID 5 is one of the most popular implementations of RAID. It utilizes the configurations of
Byte Stripping and Block Stripping, and writes the data to multiple disks. The minimum number
of drives for a RAID 5 configuration is 3. It possesses the
stripe error correction
information; therefore, once a read/write failure occurs on one drive, the system can
still read and write data using the other drive. As result, the performance of RAID 5 can
substantially decrease in a write-heavy environment.