Types of Hard Drive Connectors

Connectivity is a word you'll hear often when performing just about any hardware assessment. Hard drives are no exception when it comes to the available types of connections you have at your disposal when choosing hardware, and choosing the incorrect type can severely impair your system's performance.

Function

Unlike some hardware connection types which have no bearing on speed or performance, hard drive connections determine the communication protocols used by the hard drive to transmit data. This fact means that choosing the wrong type could adversely affect your system stability.

Types

There are three connection types of relevance when dealing with non enterprise level computers. These are EIDE (Enhanced Integrated Device), SATA/SATA II (Serial Advanced Technology Attachment), and, to a lesser extent, SAS (Serial Attached SCSI).

Misconceptions

Though SAS and SATA/SATA II use an interchangeable physical connector, they use different signaling technology. Thus, plugging a SAS drive into a SATA/SATA II port will cause the SAS drive to run at a reduced speed.

Features

Both SATA/SATA II and SAS support hot swapping capabilities, meaning you do not have to power down your computer to change out drives.

Benefits

The maximum transfer speeds for EIDE, SATA/SATA II, and SAS hard drive connections are 133 MB/s, 150 MB/s / 300 MB/s, and 600 MB/s respectively.

Resources

• Current draft revision of SAS 2 from T10
• Serial ATA International Organization Homepage
• Parallel ATA - 1 ANSI reference