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4 cache parameters, 1 optimization for sequential or random i/o – Asus PCI-DA2200 User Manual

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3-14

ASUS 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-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.