What is eSATA?

First of all, let’s get a basic understanding of SATA. These letters stand for serial advanced technology attachment. This technology is a “computer bus interface for connecting host bus adapters to mass storage devices such as hard disk drives and optical drives.” (Wikipedia).

What does all that “scientific” jargon mean? It means that computer designers and computer users have devices that “communicate via high-speed serial cable over two pairs of conductors.” This may not seem to help much but it’s a major change from the much slower speeds of earlier ATA technology.

Less Bulk, Better Results

One of the primary benefits of SATA technology is the reduction in the number of wires needed to transfer data. In fact, SATA uses about 10 percent of the number of wires needed for older ATA designs. SATA is used in most new computers and is a key part of the motherboard in desktop-computer design.

But why is there a small “e” in front of the SATA? Because eSATA is slightly different in that it is used for external connections. The basic requirements for designing and setting up eSATA are somewhat different from other serial connectivity. For example, design texts show that the range for minimum-transmit potential is 500 to 600 mV rather than 400 to 600 mV. Receive potential is slightly decreased. However, some existing SATA devices can be used with minor modification. If you look at the SATA and eSATA connectors side by side there are noticeable differences.

Now Available?

eSATA technology is part of the market that is currently dominated by universal serial bus (USB) and FireWire. Tech manuals and installation instructions show that there may be some lack of efficiency when an external hard disk has USB or FireWire connectivity that is bridged with SATA devices. In general terms, SATA specs show that the first generation of interfaces has a 1.5 gigabyte communication rate.
Some of the information about eSATA has been developed since early 2009, which means that this technology is very new in comparison to other data-transfer and storage specs. Manufacturers initially bridged their designs with specific chips. However, more recent specifications show that SATA and eSATA are progressing to the level of first-choice, native products.

SATA technology has progressed from 1.0 to SATA 2.0 and even to SATA 3.0. In fact, the focused Serial ATA International Organization was working with SATA Revision 3.0 as far back as 2008. However, release didn’t occur until well into 2009. Key elements of improved eSATA are in the areas of command queuing and hot swapping. Some of the enhancements focus on video streaming quality. eSATA has even developed its own dedicated logo to bring attention to these objectives.

One of the key elements of success with eSATA lies with manufacturers. These companies must market their drives as ATA devices so that designers and consumers are not misled. Many suppliers offer products that do not have external SATA connectors. But this is changing. Those who have no eSATA connector can upgrade their computer system with a host bus adapter or specific card.