external SATA to shed the power plug

by Stephen Shankland If your power strips are as overloaded as mine with cords and bulky transformers, you'll be glad to hear that eSATA--a standard that gives external hard drives the data transfer speeds of internal drives--is untethering itself from its power cord. eSATA is an external version of the Serial ATA technology used to hook up internal PCs, but today external eSATA drives need their own power supply. But on Monday, the Serial ATA International Organization (SATA-IO) announced it's working on a version that will let external drives draw power over the cable that connects the drive to a computer. The standard, called Power Over eSATA, is expected to be completed in the second half of 2008, and the first devices supporting the standard could arrive as soon as this year, too, the consortium said. The technology should be able to deliver enough power to run a single 2.5-inch drive, said Knut Grimsrud, the SATA-IO president and an Intel fellow, and likely will become a regular part of eSATA products. "I would expect the powered eSATA (to) quickly become commonplace for applications where eSATA is used," Grimsrud said of the new technology. The power link could help eSATA catch up to the two most common connection technologies, USB and IEEE 1394 "Firewire," which can power external hard drives. But the groups behind those standards aren't standing still--and of course those connections can link to many other devices besides hard drives. Specifically, Intel and others are working on a new fiber-optic "SuperSpeed" version of USB that should make its transfer speed to at least 4.8Gb per second, 10 times faster than today's 480 megabits per second. And the 1394 Trade Association is preparing a 3.2Gb/sec specification that should be ratified by February. That should quadruple the current top-end 800Mb/sec IEEE 1394 speed. Another weakness of eSATA today is hot-plug support, the ability to plug a drive into a running computer. "Some operating systems and/or device drivers might not yet have enabled full support for the hot-plug features that the SATA technology provides," Grimsrud said, and some legacy hardware configurations or product deficiencies can make it difficult. The Power Over eSATA technology will use the same connectors as current eSATA, but will require new cables to carry the power, Grimsrud said. The current eSATA has data-transfer connections only on one side of the plug, so the Power Over eSATA technology likely will add the power connections on the reverse side, he said.

read more | digg story