Cache Memory; Megaraid Bios; Scsi Firmware - LSI MegaRAID SCSI 320-0 Zero-Channel RAID Controller Series 520 Hardware Manual

4.9.2

Cache Memory

4.9.3

MegaRAID BIOS

4.9.4

SCSI Firmware

MegaRAID SCSI 320-0 supports 32 to 128 Mbytes of ECC SDRAM
DIMM on-board cache memory. MegaRAID supports write-through or
write-back caching, which can be selected for each logical drive. To
improve performance in sequential disk accesses, MegaRAID does not
use read-ahead caching for the current logical drive. The default setting
for the read policy is Normal, meaning no read-ahead caching. You can
disable read-ahead caching.
Warning: Write caching is not recommended for the physical drives.
When write cache is enabled, loss of data can occur when
power is interrupted.
The BIOS resides on a 1 Mbyte × 8 flash ROM for easy upgrade. The
MegaRAID BIOS supports INT 13h calls to boot DOS without special
software or device drivers. The MegaRAID BIOS provides an extensive
setup utility that can be accessed by pressing <Ctrl><M> at BIOS
initialization. The MegaRAID BIOS Configuration Utility is described in
the MegaRAID Configuration Software Guide.
The MegaRAID SCSI 320-0 firmware handles all RAID and SCSI
command processing and also supports the items in
Table 4.7 SCSI Firmware
Feature Description
Disconnect/ Optimizes SCSI bus seek.
reconnect
Stripe size Variable for all logical drives: 2, 4, 8, 16, 32, 64, or 128
Kbytes.
Rebuild Multiple rebuilds and consistency checks with user-
definable priority.
MegaRAID SCSI 320-0 Specifications
Copyright © 2002 by LSI Logic Corporation. All rights reserved.
Table 4.7.
4-7