Specifications

72 en | LCD Keypad Operation SCSI to SATA RAID Subsystem | Administrator’s Manual
F.01U.027.802 | V1 | 2006.11 Bosch Security Systems
5.12.4 Data Rate
This option is available in the configuration menu of SCSI host channel and the drive channel
configuration menus of SATA-based subsystems. Default is “AUTO” and should work fine with
most drives. Changing this setting is not recommended unless some particular bus signal
issues occur.
Most SATA/ATA-based systems connect only one drive per SATA/ATA channel (4 for multi-lane
with SATA-II). This helps to avoid a single drive failure from affecting other drives. The maxi-
mum mechanical performance of today’s drives can reach around 30MB/second (sustained
read). This is still far below the bandwidth of a drive channel bus. Setting the SATA/ATA bus
speed to a lower value can get around some problems, but will not become a bottleneck to
system performance.
Note that the SATA/ATA speed is the maximum transfer rate of the SATA/ATA bus in that
mode. It does not mean the drive can actually carry out that amount of sustained read/write
performance. For the performance of each drive model, please refer to the documentation
provided by drive manufacturer.
Host Channel:
Select from Main Menu, “View and Edit Channels,” and then a host channel you wish to
change its data rate. Press ENT on the channel and use the arrow keys to find the “Set Trans-
fer Speed” option. Press ENT on the Transfer Speed option to display “Chl=X Clk=160 Change
to=160?”, where “X” stands for the channel number.
Use your arrow keys to display a different data rate (160MHz to Async). Press ENT to confirm
a selection.
Drive Channel:
Select from Main Menu, “View and Edit Channels,” and then a drive channel you wish to
change its data rate. Press ENT on the channel and use the arrow keys to find the “Data Rate”
option. Press ENT on the Data Rate option to display “Set Chl=X Data Rate To AUTO?”, where
“X” stands for the channel number.
Use your arrow keys to display a data rate value which ranges from 33 to 150MB/s (SATA drive
channels). Press ENT to confirm a selection.