Wide Ultra2 Scsi - Asus PCI-SC896 User Manual

1.3.4 Wide Ultra2 SCSI

The PCI-SC896 has full support for Wide Ultra2 SCSI. This interface is an
extension of the SCSI-3 family of standards that expands the bandwidth of the
SCSI bus to allow faster synchronous data transfers, up to 80 Mbytes/s. Wide
Ultra2 SCSI provides a doubling of the data rate over the Ultra2 SCSI inter-
face, while it increases cable lengths and allows a larger number of devices on
the cable than Ultra2 SCSI interfaces. Special SCSI cables are specified for
operation with Wide Ultra and Ultra2 SCSI devices, and you must consider the
total number of devices and the length of your SCSI bus when setting up your
system. See Chapter 2, Installing the PCI-SC896 Host Adapter for a detailed
explanation of SCSI bus connections.
When you purchased the PCI-SC896 host adapter kit, the cable provided in the
kit is matched for a Fast/Ultra/Ultra2 SE or LVD operation. This cable also has
built-in LVD termination since most Ultra2 hard disk drives are not made with
onboard LVD termination.
Standard Cables
STA Term
Wide Ultra SCSI 1.5M
Wide Ultra SCSI 3.0M
Wide Ultra2 SCSI (2)
(1) This parameter may be exceeded in point to point and engineered appli-
cations.
(2) Single-ended and high-power differential are not defined at Ultra2 speeds.
(3) LVD was not defined in the original SCSI standards for this speed. If all
devices on the bus support LVD, then 12-meter operation is possible at
this speed. However, if any device on the bus is single-ended only, then
the entire bus switches to single-ended mode, and the distances in the
single-ended column apply.
12
1. Introduction
Maximum Bus Length (1)
Single-Ended LVD
(3)
(3)
12
ASUS PCI-SC896 User's Manual
Maximum Devices
8
4
16