Dell 3 - Manual (Page 169)

PERC 3 BIOS Configuration Utility 167
– Direct I/O specifies that reads are not buffered in cache memory.
Direct I/O does not override the cache policy settings. Data is
transferred to cache and the host concurrently. If the same data
block is read again, it comes from cache memory. This is the
default setting.
15 Press <Esc> to exit the Advanced Menu.
NOTE: The PERC 3
family supports spanning
across RAID 1 and 5
arrays only.
16 After you define the current logical drive, choose Accept and press
<Enter>.
The array selection screen appears if any unconfigured disk drives
remain.
17 Repeat steps 3 through 16 to configure another array and logical drive.
PERC 3 supports up to forty logical drives per controller.
18 If you are finished configuring logical drives, press <Esc> to exit Easy
Configuration.
A list of the currently configured logical drives appears.
19 Save the configuration at the prompt.
After you respond to the Save prompt, the Configure menu appears.
20 Initialize the logical drives you have just configured.
Using New Configuration
The New Configuration option allows you to associate logical drives with
multiple physical arrays (spanning of arrays.)
NOTICE: Choosing the New Configuration option erases the existing
configuration information on the selected controller. To use the spanning
feature and keep the existing configuration, use View/Add
Configuration.
Perform the following steps to configure the arrays using New
Configuration.
1 Choose Configure—> New Configuration from the Management
Menu.