Specifications

3 ATTO Technology ExpressPCI UL4D and UL4S Installation and Operation Manual
2 ATTO ExpressPCI provides Ultra320 SCSI solutions
The Ultra320 SCSI host adapter represents the seventh generation of SCSI technology, an I/O interface
that is committed to increased performance while maintaining backward compatibility and legacy
support. The ATTO ExpressPCI UL4S is a single channel Ultra 320 SCSI, PCI-X host adapter while the
ATTO ExpressPCI UL4D is a dual channel Ultra 320 SCSI, PCI-X Host Adapter.
Today’s computing applications continue to strain
the host PCI bus and storage subsystem. To bring
better performance and reliability to today’s
professional applications, the ATTO ExpressPCI
UL4D and UL4S adapters deliver up to 640
MB/sec. data throughput, and take advantage of
the new PCI-X bus interface and improvements in
the SCSI standard. ATTO ExpressPCI UL4D and
UL4S adapters deliver the high bandwidth
demanded in data-intensive environments such as
real-time and high-definition video editing, web
server and database engines.
What’s new in Ultra320
The Ultra3 SCSI specifications originally
included five features:
❖ Double Transition Clocking
❖ Domain Validation
❖ Cyclic Redundancy Check (CRC)
❖ Packetization
❖ Quick Arbitration Select (QAS)
Ultra320 SCSI supports all Ultra3 features plus:
❖ Free-Running Clock
❖ Read and Write Data Streaming
❖ Flow Control
❖ Training Pattern
❖ Pre-Compensation
❖ Asynchronous Information Protection
(AIP)
Common features
❖ Supports data transfer speeds of up to 320
MB/sec. per channel
❖ Supports Ultra 320 Specifications including:
❖ Packetized SCSI
❖ Double transition clocking
❖ Quick Arbitration Select (QAS)
❖ Cyclical Redundancy Checking (CRC)
❖ Domain Validation (DV)
❖ Asynchronous Information Protection
(AIP)
❖ Free-running clock
❖ Flow control
❖ Advanced Data Streaming (ADS™) provides
controlled acceleration of data transfers.
❖ Embedded RISC processor for low
overhead
❖ Bus mastering eliminates CPU
processing time as a bottleneck
❖ Tagged command queuing allows
threads to be processed efficiently
❖ Disconnect/reconnect eliminates wait
time between transfers
❖ Optimized scatter/gather lists
❖ Backward compatible with legacy SCSI
devices
❖ ASPI (Windows®) and SCSI Manager 4.3
(Macintosh®) compatible
❖ Automatic and upper-byte termination
❖ Flash ROM for easy field upgrades
❖ RAID ready
❖ Accelerated PCI bus management
❖ PCI Bus Master rate of 1-GB/sec.
❖ PCI-X 1.0a compliant
❖ PCI 2.2 compliant
❖ 64-bit/133 Mhz PCI-X (backward
compatible with standard PCI)