Seagate announced that it has sold 1 million units of the Momentus XT, the first and only mass-produced hybrid drive on the market, since the launch of the product in spring 2010.
These hybrid drives run at 7,200 RPM, nearly twice as fast as standard mechanical drives. The drives contain some solid-state memory as well as a full mechanical drive and offer speed improvements at a very low initial cost.
A hybrid drive is a combination of traditional platter-based storage and solid-state storage in one box. In the case of the Momentus XT, the drive comes in the standard 2.5-inch design (for laptops) and offers 500GB of storage space, of which 4GB is made of solid-state flash memory. The drive also features a built-in algorithm that automatically moves frequently accessed information onto the solid-state part of the drive.
I would like to clear; this isn’t a full SD drive, but the owners of existing laptops with a traditional internal hard drive can get the 500GB Momentus XT for about $99, as a replacement drive at retail stores.