
SCSI SSDs	..


iSCSI SSDs	..


SAS SSDs	..

StorageSearch.com

enterprise buyers guides since 1991

"leading the way to the new storage frontier"

20 Years of SCSI Editorial - by Zsolt Kerekes, editor

I published my first directory of SCSI host bus adapters in 1992 in a buyers guide called the SPARC Product Directory.

In 1998 I moved it here to StorageSearch.com.

To avoid ambiguity, I suppose we should refer to "SCSI" nowadays as "parallel SCSI" to differentiate it from the "serial" kind.

Old style SCSI hasn't disappeared entirely. Some companies are still making compatible SSDs for example.

See also:- SCSI - editor mentions - here on the mouse site.

What is SCSI?
the Solid State Disks Buyers Guide
LVD, SE, HVD, SCSI compatibility - or lack of it
SCSI Software Tools for Defense Systems Integrators
Serial Attached SCSI: New Interface, New Storage Rack?
the Benefits of Serial Attached SCS) for External Subsystems
Serial Attached SCSI - Delivering Flexibility to the Data Center

Megabyte found that SCSI was a safe
and reliable way to connect between
storage systems.

SCSI - Small Computer System Interface:- is a high performance parallel interface for connected mass storage devices such as disk drives to a computer.

Originally specificied using logic level (TTL) signals over ribbon cable to daisy chain upto 8 devices, this standard has been enhanced over the years to include newer voltage levels, higher speeds and more devices. The standard enables large amounts of data to be requested using a small number of intelligent commands. Dur to the popularity of this standard some manufacturers have developed extenders which enable connection over a long distance, converters such as IDE to SCSI, and routers which translate the SCSI interface and commands to fibre channel compatible signals.

Newer variations such as Serial Attached SCSI and Internet SCSI preserve compatibility at the SCSI driver and command set level, but offer different connection and routing methods.

...from Megabyte's Storage Dictionary

the Benefits of SAS (Serial Attached SCSI) for External Subsystems

This introduction to Serial Attached SCSI (written by by Adaptec) gives you an idea of the performance, compatibilities, applications and roadmap for this new directly attached disk connection standard. With throughput capability faster than 2Gbps Fibre-channel systems and faster than ultra320 SCSI - the new SAS products not only provide an upward migration path for parallel SCSI applications but also open the door to a new class of high performance high reliability enterprise systems. ...read the article, ...Adaptec profile, Serial Attached SCSI

3.5" Ultra Wide SCSI Fast Flash Disks
from M-Systems

2003 featured product from SSD market history

Serial Attached SCSI - Delivering Flexibility to the Data Center

If you think you already know SAS because you know SATA and traditional SCSI then think again. Sometimes disruptive technologies wear an unassuming disguise. In fiction, Clark Kent, Frodo Baggins and Buffy Summers at first seem harmless, but we see them change into Superman, the Ring Bearer and the Slayer.

SAS too comes cloaked in plain garb - with a physical layer which looks a lot like SATA. But like the Incredible Hulk there are muscles rippling under that shirt - and you would be wrong to dismiss SAS so lightly. There's a lot more inside this interface than it says on the box as this informative article (written by article by LSI Logic and Maxtor) reveals. ...read the article, Serial Attached SCSI

Nibble Re: SCSI

25 years old in May 2006, the SCSI standard has withstood the test of time remarkably well. Part of the reason is that there are actually 3 critical parts to this standard

the connector and cable standard:- which has evolved and adapted over the years. There's no such thing as a standard SCSI cable. In reality there are many.

the electrical levels:- which started out as TTL compatible 5V levels and have gradually dropped in level (to provide more speed) and added differential signals (to improve noise immunity).

the software protocol:- has been the key to SCSI's long term success, because conceptually it provides simple high speed access to data bytes or blocks, on a simple network of connected storage devices.

The performance of the SCSI connection has always enable state of the art disk I/O to be supported at hardware speeds. In fact the software standard has proved so useful, that it's been adopted in the next generation internet connected storage standard iSCSI.

SCSI longevity has been due to the fact that it incorporates a handful of basic concepts which have been flexible enough to be expanded and adapted as new faster electronic interface technologies and devices came along.

Just as Ethernet changed speed from 3Mbits/S, then 10Mbits/S, 100Mbits/S, and now 1000Mbits/S (Gigabit Ethernet), SCSI now spans the speed range from its original 5Mbytes/S to 320Mbytes/S . That's fast enough for most applications, and ensures that it will still be a safe economical choice for many years to come.

In fact the legacy software established with the SCSI protocol has led to 2 other variants developing in recent years.

iSCSI - which connects remote locations via an emulation of SCSI which operates over the internet, and

Serial Attached SCSI - this is an emerging standard, which aims to provide a low cost, high performance alternative to FireWire.

Market research on
STORAGEsearch.com

Market research can help you avoid going down a dead end track.