While it's easy to make a thin SSD for low-profile laptops and other mobile computing devices, NAND memory isn't cheap. Designers are constantly faced with a choice between capacity and affordability. While 2.5-inch hard drives are about one-fifth the cost of SSDs,their 7- or 9mm profiles rendered them difficult to implement in ultraportables and other smaller laptops. That's why the Seagate Laptop Ultrathin HDD is big… err small news. See all hard drive reviews.
At 94g and just 5mm thick, it provides 500GB of relatively cheap storage that eases the price/capacity design conundrum.The drive has a SATA 6Gbs interface, but its platter spins at only 5400 rpm, so you shouldn't expect extremely high performance. See also: SSD buying advice.
In our tests, the drive wrote our 10GB mix of files and folders at 73.8MBps, it read them at 91.1MBps, and it handled our single large 10GB file at 151.4MBps (write) and 100.2MBps (read). That's not bad given the spindle speed, but it's hardly SSD-like—or even 7200 rpm-like. Hands-on with a relatively speedy laptop, our Windows installation felt decently responsive but that has a much to do with Windows advanced caching as the speed of the drive. See our group test: What's the best SSD?
Seagate's Laptop Ultrathin hard drive is about the same thickness as four credit cards.
The Laptop Ultrathin HDD is rated to survive up to a 400G shock while running and 1000Gs when powered down. Those are some pretty hefty ratings. We didn't perform any drop tests, but in my relatively uncaring hands-on with the drive powered up and spinning outside the case, it survived several small shocks.
Other possible upsides to the 5mm form factor could be multiple hard drives in standard-sized laptops. Two Laptop Ultrathin HDDs in a RAID 1 setup could provide the redundancy that most laptops lack, or in a RAID 0 array compensate for the slow-ish performance of the drive. The thin size also allows for beefier shock-mounting in devices that have room for it.