- IBM is perfecting a solid-state memory technology that, like flash memory chips, is intended to replace hard disk drives with devices that have no moving parts. And even better than flash, IBM's racetrack memory does not wear out no matter how many times you read, write or erase it.Magnetic memory technologies—notably hard disk drives—can be read, written and erased any number of times, since the only changes made are in the orientation of the magnetic material on its surface, which does not fatigue. Unfortunately, solid-state memories like flash will never completely replace hard disks because they fatigue and wear out after about 10,000 read/write cycles.
Now, however, IBM has developed a magnetic memory technology that combines the no-moving-parts convenience of a solid-state solution with the speed, reliability and longevity of a hard disk drive.
Racetrack memories have been the object of intense research efforts by IBM since 2004, when the major processes were patented by the company. Since then, IBM's research team has demonstrated all the component parts needed to read, write and erase magnetic bits serially encoded around a nanowire racetrack, similar in concept to the tiny magnet tracks around a hard disk platter. However, instead of rotating the disk to bring each bit in a track under the read head of the drive, an electrical current is used to push the bits around the nanowire track so that they can be read by a stationary head.
IBM has demonstrated all the component parts of its racetrack memory, which moves magnetic bits along a stationary nanowire "track" that stores hundreds of times more information than even the densest hard disk.
Magnetic information is encoded along the entire length of a nanowire track—each of which can fit in the space that a single flash memory bit occupies today, resulting in memories that are 100 times denser than hard disks and 10 times denser than flash memory. And unlike flash memories, which must use high-voltage currents to force electrons to tunnel through an insulator that fatigues and fails after just a few thousand read/write cycles, there are no atoms being shifted around to cause racetrack memories to fail, resulting in a solid-state memory technology that is denser than hard disks but with more longevity than flash.
"We move the magnetic information without moving any atoms," said IBM Fellow Stuart Parkin. "An electrical current essentially delivers angular momentum that moves the magnetic domain walls around the track."
By loading each racetrack with a serial string of magnetic bits, and shifting them around the nanowire, the solid-state memory essentially houses thousands of independent magnetic tracks, each of which can be independently shifted to read/write/or erase any bit on its length—like a hard drive, but without the moving parts.
Recently, IBM cleared the last hurdle to commercialization of racetrack memories by demonstrating that it can deliver current pulses that can accurately and repeatably move any bit around a racetrack nanowire and position it under the read or write head. Next, IBM will integrate all the components onto a single CMOS chip.
- Racetrack Memory Aims to Replace Flash/HD