Cisco CloudCenter: Get the Hybrid IT Advantage


Definition - What does SCSI-3 mean?

Small Computer System Interface 3 (SCSI-3) is an ongoing standardization effort for extending the features of SCSI-2. The key goals of SCSI-3 include the following:
  • Additional devices on a bus (as many as 32)
  • Increased distances between devices (longer cables)
  • Speedy data transfer
  • More command sets and device classes
  • Structured protocol model
  • Structured documentation

Techopedia explains SCSI-3

The SCSI-3 standard is a collection of other standards. These standards are arranged into a framework based on the SCSI-3 architecture documents. Used in several high-end systems, SCSI-3 often utilizes a MicroD 68-pin connector having thumbscrews. It is also referred to as Mini 68.

The most widely used bus width for SCSI-3 is 16 bits, with a transfer rate of 20 MBps.

In SCSI-2, data is transmitted in parallel (i.e., 8, 16 or 32 bits wide). This can get significantly challenging with longer cables and higher data rates owing to varying signal delays on various wires. In addition, drive power and wiring expenditure grow with higher speeds and wider data words. This has triggered the migration to serial interfacing in SCSI-3.

Issues with delay are eradicated by embedding clock information to serial data stream signals. Also, driving a single signal uses up less driving power and cuts down connector price and size.

In order to permit backward compatibility and increased flexibility, SCSI-3 permits the use of many different transport systems, some parallel and some serial. For every transport, the command set and software protocol are the same. This results in a layered protocol definition that is much like the definitions present in networking.

SCSI-3 therefore is the sum of quite a few independent standards that are based on independent groups.
Share this:

Connect with us

Email Newsletter

Join thousands of others with our weekly newsletter

The 4th Era of IT Infrastructure: Superconverged Systems
The 4th Era of IT Infrastructure: Superconverged Systems:
Learn the benefits and limitations of the 3 generations of IT infrastructure – siloed, converged and hyperconverged – and discover how the 4th...
Approaches and Benefits of Network Virtualization
Approaches and Benefits of Network Virtualization:
Businesses today aspire to achieve a software-defined datacenter (SDDC) to enhance business agility and reduce operational complexity. However, the...
Free E-Book: Public Cloud Guide
Free E-Book: Public Cloud Guide:
This white paper is for leaders of Operations, Engineering, or Infrastructure teams who are creating or executing an IT roadmap.
Free Tool: Virtual Health Monitor
Free Tool: Virtual Health Monitor:
Virtual Health Monitor is a free virtualization monitoring and reporting tool for VMware, Hyper-V, RHEV, and XenServer environments.
Free 30 Day Trial – Turbonomic
Free 30 Day Trial – Turbonomic:
Turbonomic delivers an autonomic platform where virtual and cloud environments self-manage in real-time to assure application performance.