LSI MegaRAID Express 500 - Manual (Page 48)

MegaRAID Express 500 Hardware Guide 34
SCSI Bus
MegaRAID Express 500 has a Fast and Wide Ultra 160M SCSI channel that supports
both LVD and single-ended devices with active termination. Synchronous and
asynchronous devices are supported. MegaRAID Express 500 provides automatic
termination disable via cable detection. The SCSI channel supports up to 15 wide or
seven non-wide SCSI devices at speeds up to
160 MB/s. MegaRAID Express 500 supports up to
six non-disk devices per controller.
SCSI Connectors
MegaRAID Express 500 has two types of SCSI connectors:
• a 68-pin high density internal connector
• a 68-pin external ultra-high-density connector
Both connector types can be used for the SCSI channel.
SCSI Termination
MegaRAID Express 500 uses active termination on the SCSI bus conforming to
Alternative 2 of the SCSI-2 specifications. Termination enable/disable is automatic
through cable detection.
SCSI Firmware
The MegaRAID Express 500 firmware handles all RAID and SCSI command processing
and also supports:
Feature Description
Disconnect/
Reconnect Optimizes SCSI Bus seek.
Tagged Command
Queuing Multiple tags to improve random access
Scatter/Gather Multiple address/count pairs
Multi-threading Up to 255 simultaneous commands with elevator sorting and
concatenation of requests per SCSI channel
Stripe Size Variable for all logical drives: 2 KB, 4 KB, 8 KB, 16 KB, 32
KB, 64 KB, or 128 KB.
Rebuild Multiple rebuilds and consistency checks with user-
definable priority.