HP Vectra XU 6/XXX Optimization Manual page 20

Multithreaded Operating System Support
The PCI SCSI controller in your PC offers additional performance advantages under
multithreaded operating systems. Your PC's integrated SCSI controller is capable of receiving
and processing the multiple commands issued by a multithreaded operating system. The SCSI
controller is also able to re-order operating system commands to obtain the most efficient
execution order.
Ultra SCSI-Ready
The SCSI channel in your PC supports the latest SCSI standard, Ultra SCSI, which gives data
transfer rates of up to 20 MB per second. As new mass storage devices supporting this
standard become available, you will be able to make use of them immediately. Installing an
Ultra SCSI device in your PC will offer a performance improvement over previous generation
SCSI devices.
Investment Protection
Use of the high speed Ultra SCSI transfer rates does not exclude the connection of slower
SCSI devices on your PC's SCSI channel. Mixing SCSI devices of different generations will not
cause any conflicts in your PC's operation.
Three types of 8-bit SCSI devices are supported:
• SCSI-1 devices
These are first generation SCSI devices and support data transfer rates of up to 5 MB/s.
• SCSI-2 devices
The previous generation of SCSI devices that support data transfer rates of up to 10 MB/s.
• Ultra SCSI devices
The latest SCSI devices. These support data transfer rates of up to 20 MB/s.
Your PC's advanced SCSI controller can manage SCSI devices of all three types
simultaneously.
When installing a SCSI device, the data transfer rate for that device must be configured
correctly. SCSI data transfer rates can be set independently for each SCSI device installed
using the SCSISelect Utility. Refer to your User's Guide for information on this Utility.