Hardware Installation and User’s Guide
27
Hardware Specifications and Features
3.4
Supported SCSI Technology
The GDT8522RZ and GDT8622RZ ICP RAID Controller products support up to 15
physical SCSI devices for the internal SCSI channel. They support up to 15 hard disk
drives or 14 hard disk drives if one of the SCSI IDs is occupied by a SAF-TE processor.
3.4.1
Supported Hard Drive Technology
The GDT8522RZ and GDT8622RZ ICP RAID Controller products support both
Single-
ended (SE)
and
Low Voltage Differential (LVD)
devices but it is recommended that you
use only one type of drive technology (SE or LVD) on any one channel at a time. See
Table 3-4
for the Supported SCSI Device Standards. These ICP RAID Controller products
are designed to optimally utilize Ultra160 SCSI devices, yet they are backward
compatible with older SCSI hard drive specifications.
Note:
If both SE and LVD devices are attached to the same channel/bus, the entire bus must
operate at the single ended mode speed of the slower device. See
Table 3-4
for the
maximum cable length distances that apply to each mode.
Table 3-4. Supported SCSI Device Standards
SCSI Drive
Standard
Bus Speed
(MB/Sec)
Bus Width
(in Bits)
Maximum Cable
Length (meters)
(1)
Maximum Devices
per SCSI Channel
Single-
Ended
LVD
SCSI-1
(2)
5
8
6
(3)
8
Fast SCSI
(2)
10
8
3
(3)
8
Fast Wide SCSI
20
16
3
(3)
16
Ultra SCSI
(2)
20
8
1.5
(3)
8
Ultra SCSI
(2)
20
8
3
N/A
4
Wide Ultra SCSI
40
16
N/A
(3)
16
Wide Ultra SCSI
40
16
1.5
N/A
8
Wide Ultra SCSI
40
16
3
N/A
4
Ultra 2 SCSI
(2, 4)
40
8
(4)
12
8
