Introduction
Back in the old days when the bulletin board services (BBSes) ruled, SCSI was king of speed for hard drives. But because they were extremely expensive, most people just used IDE hard drives. Even today, IDE drives remain the most popular type of hard drives.
The IDE standard is now over 20 years old. When measured against the lifecycle of a processor, it's like going to your friend's place and playing on his Sega Genesis! With speed being the primary consumer driver, it's about time that the storage market got a jump start with a new drive communication standard - Serial ATA (SATA).
In this article, I will go over the motivations for the Serial ATA standard and how it will affect the industry. This is meant to be a general overview of the technology without getting into the gory details. But I will throw in some voltages for giggles.
Why A New Standard?
The current hard drive standard is known as IDE or Parallel ATA. Many in the industry believed that technologies such as SCSI would eventually replace IDE.
However, the main issue with SCSI is the need for a SCSI controller (through either an add-on card or new motherboard) which increased costs. The problem with IDE is its limited data rate which tops out at about ~150MB/sec.
To compensate, manufacturers have progressively increased disk rotation rates and used larger buffers. Unfortunately, these have the undesirable side-effects of making the drives louder and hotter. Also, the IDE standard with its large cables caused problems with air flow and heat dissipation inside computer cases.
The solution? Serial ATA!
Seagate Barracuda ATA V Serial ATA hard drive
Courtesy, Seagate
Serial ATA has a very aggressive timeline and schedule on what it would like to do.
|
Generation 1
|
Generation 2
|
Generation 3
|
Approximate speed (8b side)
|
1.2 Gbits/s
(150 Mbytes/sec) |
2.4 Gbits/s
|
4.8 Gbits/s
|
Approximate speed (10b side)
|
1.5 Gbits/sec
|
3.0 Gbits/sec
|
6.0 Gbits/s
|
Estimated introduction date
|
Mid 2001
|
Mid 2004
|
Mid 2007
|
Connector
|
-
|
Same as Gen 1
|
May be upgraded
|
Cable
|
-
|
Same as Gen 1
|
May be upgraded
|
Signaling compatibility
|
-
|
Compatible with Generation 1
|
Compatible with Gen 2
May be compatible with Gen 1 |
Table from SATA.org