ATTO Technology operation manual Scsi is a key technology for storage, Glossary

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2 SCSI is a key technology for storage

SCSI is a serial communications technology designed to transfer large amounts of data between a variety of hardware systems over long distances. It is a key technology for applications that require shared, high bandwidth access to storage.

SCSI provides a logical point-to point serial channel for the transfer of data between a buffer at a source device and a buffer at a destination device. It moves buffer contents from one port to another, without regard to the format or meaning of the data so different upper level protocols are able to run over SCSI hardware.

The SCSI architecture is structured as a hierarchical set of protocol layers. Defined within these layers are rules for signal interfaces, serial encoding and decoding, error control, frame format and communications protocols.

Glossary

Some terms used in the SCSI industry are defined below. More information is available through the ATTO Technology website (www.attotech.com), and the SCSI Consortium (www.iol.unh.edu/consortium).

Term

Definition

ANSI

American National Standards Institute

auto negotiation

hardware senses and automatically responds depending on configuration

BER

Bit Error Rate: a measure of transmission accuracy; the ratio of bits received in

 

error to bits sent

bit

Smallest unit of data a computer can process: a single binary digit with a value

 

of either 0 or 1

byte

an ordered set of 8 bits

CRC

Cyclic Redundancy Check: an error-correcting code which calculates a numeric

 

value for received and transmitted data. If no error has occurred during

 

transmission, the CRC for both received and transmitted data should be the

 

same.

host

a processor, usually a CPU and memory, which communicates with devices

 

over an interface

initiator device

A component which originates a command

LED

Light-emitting diode: a type of diode that emits light when current passes

 

through it. Visible LEDs are used as indicator lights on all sorts of electronic

 

devices.

originator

an initiating device; a component which originates a command

receiver

the ultimate destination of data transmission; a terminal device

3 ATTO Technology ExpressPCI Ultra/WIDE SCSI Host Adapters Installation and Operation Manual

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Contents Page Page Contents Environmental and Physical Specifications FeaturesPower Requirements Scsi ConnectorsFeatures, benefits Scsi is a key technology for storage GlossaryGlossary Installing the ExpressPCI Scsi Host Adapter InstallationSystem requirements Atto ExpressPCI PSC Scsi adapter Connectors Cable typesExamples Connection considerations TerminationTo set up cabling and termination Wide devices first closest to the connectorCables, termination Installing and Updating Device Drivers Windows Server 2003 & Windows 2000/XPDrivers Re-flashing Firmware in Windows Updating Drivers and Re-flashing Firmware in Mac OS Set up RAID groups with Atto ExpressRAID Use the latest Atto driverSet registry for large block transfers Increase transfer size Analyze your I/OsTroubleshooting Troubleshooting Appendix a Standards and compliances FCC standards radio and television interferenceSpecific features Appendix B Scsi host adapter selection guideAppendix C Fibre Channel host adapter guide ExpressPCI Express PCIAppendix D Contact Atto Technology, Inc

ATTO ExpressPCI Ultra/WIDE SCSI Host Adapters Express PCI PSC: Single-Channel Single-Ended Ultra/WIDE ExpressPCI DC: Dual-Channel Single-Ended Ultra/WIDE specifications

ATTO Technology is a leading provider of cutting-edge storage connectivity solutions, and their line of ATTO ExpressPCI Ultra/WIDE SCSI Host Adapters has showcased the company’s commitment to performance and reliability for demanding data applications. Specifically, the ExpressPCI PSC (Single-Channel Single-Ended Ultra/WIDE) and the ExpressPCI DC (Dual-Channel Single-Ended Ultra/WIDE) models cater to different user needs while maintaining industry standards.

The ATTO ExpressPCI PSC is designed for environments where a single channel is sufficient to meet the connectivity demands. This single-ended adapter supports Ultra/WIDE SCSI technology, enabling data transfer rates of up to 40 MB/s. The PSC is perfect for users who require efficient storage solutions without the complexity of handling multiple channels. With its robust design, this adapter excels in various applications, from small business servers to high-performance workstations, offering reliability in demanding environments.

On the other hand, the ATTO ExpressPCI DC doubles the capability with its dual-channel architecture. This feature allows for two independent SCSI buses, effectively doubling the potential data throughput. By utilizing ultra/WIDE SCSI technology, the DC can achieve a combined throughput of 80 MB/s, making it an optimal choice for users needing higher performance for tasks such as video editing, data intensive applications, and backups. The dual-channel configuration provides advantages in multitasking, enabling the simultaneous operation of multiple drives or devices.

Both models incorporate advanced technologies such as automatic bus termination and active negation, ensuring optimal signal integrity and reliability. Additionally, ATTO’s exclusive Advanced Data Flow Management technology enhances performance by intelligently managing data transfer to optimize bandwidth utilization, which is key in environments where data transfer speed and reliability are crucial.

Another noteworthy characteristic is the high compatibility with various operating systems and SCSI devices, making the ExpressPCI Ultra/WIDE SCSI Host Adapters versatile and easy to incorporate into existing systems. They support a wide range of SCSI drives and peripherals, ensuring that users can leverage their investment in both current and future technologies. In summary, the ATTO ExpressPCI Ultra/WIDE SCSI Host Adapters—PSC and DC—represent robust solutions that blend speed, reliability, and flexibility, catering to the diverse needs of businesses and advanced users alike. With their proven performance, these adapters continue to be an important asset in high-demand data environments, showcasing ATTO's dedication to innovation in the storage connectivity realm.
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