|
SCSI - Ultra320 SCSI
| Ultra3
| Ultra160 | Ultra320 | Ultra2 vs Ultra160 | Dual vs Single CHannel | SCSI ASICs |
- What are the differences between Ultra320 SCSI and Ultra160 SCSI?
Differences include paced data transfer, doubling of the speed, and expander communications.
How does Ultra320 SCSI achieve a transfer rate of 320 MBytes/sec?
A
free running clock and driver pre-comp and/or optional receiver AAF, are the main keys to the higher speed. The clock runs twice as fast in Ultra320 SCSI as in Ultra160 SCSI.
What is Packetized SCSI and how does it benefit Ultra320 SCSI?
Packetized SCSI transfers bundled commands, messages and status bytes at full data transfer speeds, reducing the protocol overhead. Packetization also allows the transfer of multiple commands or data from
multiple I/O processes in a single connection.
What does QAS do?
Quick Arbitration and Selection
reduces the bus arbitration and device selection time by eliminating bus free time. Bus free time is the interval at which a device can hand the bus to another device without entering a new arbitration phase.
Is Ultra320 SCSI just as reliable as Ultra160 SCSI?
Pre-comp and/or
optional receiver AAF, skew compensation and SCSI Domain Validation (SDV) ensure that Ultra320 SCSI systems are capable of running reliably at higher speeds.
Is Ultra320 SCSI compatible with prior versions of SCSI?
SCSI devices
are always backward compatible. When newer SCSI devices are attached to a system with devices from a previous generation, the newer devices will back down to the maximum operating speed of the older generation
when they are talking. When not talking to older devices, the newer devices operate at their normal speeds.
Is Ultra320 SCSI better than Ultra160 SCSI?
Yes. Ultra320 SCSI adds
greater speed, reduced overhead, training patterns, compensation for system losses and system mapping with diagnostic capabilities for expanders. Ultra320 SCSI is better protected since the command, message, and
status information are protected by CRC.
What applications are best suited for Ultra320 SCSI?
Ultra320 SCSI is
best suited for servers, network storage, high-end workstations and RAID storage applications.
|
