Dell Precision T7400 (Late 2007) - Manual (Page 40)

40 Advanced Features
NOTE: RAID levels do not represent a hierarchy. A RAID level 5 configuration is not
inherently better or worse than a RAID level 0 configuration.
The RAID controller on your computer can only create a RAID level 0
configuration using two to four physical drives. A RAID level 5 or 10 array
(only available with the optional PCI Express RAID controller) must be made
up of three or four drives.
All drives must be the same type of drive; SAS and SATA drives cannot be
mixed in a RAID array. The drives should also be the same size to ensure that
the larger drive does not contain unallocated (and therefore unusable) space.
NOTE: RAID levels do not represent a hierarchy. A RAID level 10 configuration is
not inherently better or worse than a RAID level 0 configuration.
RAID Level 0
RAID level 0 uses a storage technique known as "data striping" to provide a
high data access rate. Data striping is a method of writing consecutive
segments—or stripes—of data sequentially across the physical drives to create
a large virtual drive. Data striping allows one of the drives to read data while
the other drive is searching for and reading the next block.
Another advantage of a RAID level 0 configuration is that it utilizes the full
capacities of the drives. If you have two 120-GB drives installed, you have 240
GB on which to store data.
hard drive 1
segment 1
segment 3
segment 5
hard drive 2
segment 2
segment 4
segment 6
SATA RAID
configured for
RAID level 0