Thursday, March 08, 2007

Serial ATA shrinks to grow

Like many things in electronics, smaller is often better. The Serial ATA International Organization announced version 2.6 of the 3 Gbit/second SATA spec this week, now available for download free to members and at a cost of $25 to non-members. Two new small connectors are the main highlights of the revision.

An "internal slimline" cable and connector will help SATA optical drives slot into smaller form factor systems. An "internal micro" aims to slip 1.8inch hard drives into the possibly emerging category of ultra-mobile PCs.

Length is the figure of merit on the new connectors here. The slimline measures 28.7 x 5.4 x 5 mm and the micro is 35 x 4 x 5 mm compared to the existing standard which was 42.73 x 3 x 5 mm.

The spec also includes an enhancement to native command queuing (NCQ) so a host CPU can quickly park the head of the hard drive when a laptop containing the drive is dropped. OEMs have been putting accelerometers in notebooks for a while to make sure heads are parked to protect media before a falling system hits the floor.

NCQ has been a nice feature to bolster performance of SATA drives, but it gets in the way of this particular scenario. It is "unacceptable to wait" for potentially 30 outstanding NCQ commands to complete before parking the head when a notebook is in freefall, a spokesman noted. No kidding!

The big picture here: Serial ATA, far and away the most successful storage interconnect in years, is making its way into the portable world in a big way. There's plenty of curl in this big wave.

No comments: