Asus PCI-DA2200, User Manual

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ASUS PCI-DA2100/PCI-DA2200 User’s Manual
IMPORTANT:
The “Verification on LD Normal Drive Writes” method will affect “write”
performance during normal use.
3.4 Cache Parameters
3.4.1 Optimization for Sequential or Random I/O
When using RAID with applications such as video or image oriented
applications, the application reads/writes from the drive using large-
block, sequential files instead of small-block, random access files. The
ASUS PCI-DA2100/-DA2200 RAID controller provides the options to
optimize for large-sequential I/O or optimize for small-random I/O
access.
“Optimization for Sequential I/O” provides a larger – 128K – stripe
size (or “block” size, also known as “chunk” size) than does
“Optimization for Random I/O” (with a size of 32K). A lot of the
controller’s internal parameters will also be changed to optimize for
sequential or random I/O. The change will take effect after the
controller reboots.
If the existing logical drives were built with “Optimization for
Random I/O”, these logical drives will not read/write when using
“Optimization for Sequential I/O” (shows "INVALID") and vice
versa because the stripe size is different. Change it back to the
original setting and reset the controller to make available the logical
drive data again.
IMPORTANT:
Changing the setting to “Optimization for Sequential I/O” or
“Optimization for Random I/O” should be performed only when no logical
drive exist. Otherwise, you will not be able to access the data in the logical
drive later on.