X-bit labs

External SerialATA Interface: First Facts about the Unannounced Standard (page 2)

Category: Storage

by Nikita Nikolaichev

[ 03/01/2004 | 10:37 AM ]

Now let’s set all the major questions, which determine the peculiarities of the external SerialATA interface implementation.

The principles implied by the very first specifications of the physical SerialATA are known to allow using the signal interface SerialATA cable up to 1 meter long and connecting an external device to it. HighPoint Company has been a supplier of pseudo SerialATA external controllers and drives, and all last year they were improving their e.SATA product line. Among these e.SATA devices from HighPoint there are separate controller cards, as well as packages including controllers, cables and the corresponding external drives. The advantages provided by the RocketRAID 1542 PCI card are more than evident, because with this card installed the user gets 4 SATA channels (2 internal and 2 external ones) with hot swap and RAID 0, 1, 0/1, JBOD support for Windows 9x/ME/NT4.0/2000XP, Red Hat, SuSE, Turbo, Caldera Linux and FreeBSD. Those of you, who already have a mainboard with the integrated SerialATA controller, can get a simple package from highpoint, including a bracket for the external SerialATA cable.

Another version of the SATA support implementation has been suggested by Gigabyte Company. They supply some of their mainboards with an additional cable and a special bracket with the laid out two SerialATA connectors and a power supply connector.

It is a pity but the new approach is not controlled by the standard and the proper performance of the package is totally within the manufacturer’s responsibility when we are talking about a non-standard device like that. As an example of the problems you might encounter when you connect external devices via the internal SerialATA version I could mention at least the fact that the standard warns against moving and shaking the interface cable during work. The acceptable signal level for internal devices and the cable screening requirements cannot ensure the desired protection against noises and distortions when you work with an external device. And the relatively weak connector used for internal solutions is beyond any criticism at all, if you decide to use it for external storage drives.

All these things push you to the conclusion that external SerialATA requires different signal levels and a longer and better screened interface cable with a completely different secure connector.