Communicator e3000 MPE/iX Release 7.0 Express 1 (Software Release C.70.01) (30216-90328)

64 Chapter4
PCI-SCSI Device Adapter Cards
PCI-SCSI Device Adapter Cards on HP e3000 N-Class and A-Class Systems.
The above “Maximum Data Rate” values are maximums that these cards can achieve.
Actual Maximum Data Transfer Rates are dependent upon a number of factors including
the type of peripheral, the storage enclosures that these peripherals are placed within and
the cables used to connect them. For example:
• SCSI-1 Devices were only certified to operate on the HP e3000 at SCSI-1 speeds. While
it is possible that newer SE-SCSI disks are capable of working at higher speeds they
are not certified to do so.
• HP6000 Series Mass Storage products (a.k.a. “Cars” boxes) and High Availability
Storage enclosures (A3311A, A3312A, a.k.a. “Jamaica”) will not support transfers at
higher than “Fast” speeds (e.g. Ultra or Ultra2).
• A5616A “SureStore E Disk System HVD10” uses HVD signaling and LVD Disk modules
but internal components are SE-SCSI based. Since SE-SCSI signaling is not defined at
“Ultra2” speeds (see Table 4-2) this cabinet is limited to Ultra speeds.
The PCSCSI DAM software will, by default, limit the bus operating speed based upon the
detected bus type according to the following rules:
1. If there is one or more SCSI-1 devices on a bus then the card will operate at “SCSI-1”
speed.
2. Except where rule #1 applies the software will set the bus speed to “Fast.”
CAUTION Overriding software defaults to operate devices at faster than certified speeds
can cause erratic system behavior, hangs and even data corruption.
Ultra2 SCSI A5149A, A5150A (LVD/SE) 8 40
Wide Ultra2 SCSI “ “ 16 80
Table 4-2. SCSI Bus Length vs. Number of Devices by Bus Type
SCSI Classification SE (Meters) HVD (Meters) LVD (Meters) Maximum Allowed
Devices (Note 2)
SCSI-1 6 25 12.5 8
Fast SCSI 3 25 12.5 8
Fast Wide SCSI 3 25 12.5 16
Ultra SCSI 1.5 25 12.5 8
Ultra SCSI 3 -- -- 4
Wide Ultra SCSI -- 25 12.5 16
Table 4-1. SCSI Bus Widths and Speeds
SCSI Classification HP Card Id (signal type) SCSI Bus Width
(Bits)
Maximum Data Rate
(MegaBytes/Sec)