updated 02:18 pm EDT, Tue October 23, 2012
Fusion drive combines SSD with hard disk using software
Apple has announced it is releasing a new drive system for its computers, designed to offer both speed and high capacities. The Fusion Drive uses both solid state storage and a larger capacity hard drive in tandem, offering the high-speed file access of an SSD combined with the cheaper and bigger capacity of traditional storage drives.
Phil Schiller called the system "fused together with software", where despite being two different storage disciplines, they are combined into one physical drive. While the SSD stores files that need to be quickly accessed, such as the operating system and applications, the spinning drive stores documents, music, videos and other files, namely items not requested as often or are not as urgently required as others.
Both the newly announced Mac mini and Mac will gain the Fusion Drive system, with options for hard disks between 1TB and 3TB in size combined with a 128GB SSD.
SSDs have been used in a similar capacity to Fusion Drive in the past. While not physically the same drive, SSD caching systems perform a similar function, by acting like a high-speed buffer between the computer system and the main storage The SSD cache automatically stores repeatedly-requested files, and provides them to the system instead of waiting for the main drive to spin up, locate, and serve what's needed.