The US Patent & Trademark Office has published a patent from Apple that details a hybrid drive system using a traditional hard drive and flash memory. Unlike current hybrid systems that focus solely on performance gains, Apple’s system would be used to prevent data loss in notebooks as well as boost system speed.
As described by Patently Apple in layman’s terms, the system would be comprised of a hard drive, flash memory, an interface circuit and a control logic. When data needs to be written to the hard drive, the control logic will do just that. But in the event that there is a change in environmental state during the write operation, the control logic will write that data to the flash memory.
Environmental state changes could include things like a change in temperature, acceleration of the hard drive (dropping the notebook) and/or vibration of the HDD. In addition to backing up data to flash, one or more transducers (heads that read data on the hard drive) may be locked briefly to prevent damage to the platter.
Additionally, the patent indicates that Apple could also use the technology to store the operating system and basic system services on the flash memory, resulting in SSD-like performance.
Hybrid storage technology has been around for a few years now and the same can be said for locking hard drive heads when excessive movement is detected. Seagate’s Momentus XT caches data using flash memory alongside a traditional spinning platter to boost overall performance. Intel’s Smart Response Technology on Z68 boards essentially does the same thing by combining a physical hard drive with a solid state drive, although much more effectively than Seagate's 2.5-inch all-in-one offering.