The goal is to create a memory chip that holds its content without power, but has the speed and random access capability of dynamic RAM (DRAM) and static RAM (SRAM), the main memory and cache memory chips in today's computers. Such future chips are expected to initially provide an alternative to flash memory and eventually replace DRAM and SRAM, and ultimately the hard disk.
The flash memory in common use in camera cards, USB drives and the like is NAND flash. It is non-volatile, but must be written in blocks similar to disk sectors, which makes it slower. DRAM and SRAM are fast and can be written one byte at a time, but lose their content without power. Both flash, DRAM and SRAM have drawbacks the industry would love to eliminate. In the meantime, the life of flash memory is also being extended (see charge trap flash).
The new memory technologies in various stages of development or implementation are phase change memory, programmable metallization cell, MRAM, F-RAM, NRAM and memristor.
An Eventual Paradigm Shift
Any memory technology that replaces flash memory will be a huge success. However, the non-volatile technology that succeeds in replacing the DRAM chips used for main memory will dramatically change the way software is written and systems are architected. All operating systems and applications are designed to continuously save data to the disk. When main memory finally "remembers" like it did in the old days of core memory (why it was originally called "memory"), many data elements will reside in memory at all times. In addition, computers will be "instant-on" and not waste AC or battery power when idle.
The Ultimate Outcome
When one compares the internal magic of any solid state memory chip with a hard disk, it becomes very apparent that although hard disks are highly reliable and used by the billions, they represent an antiquated architecture compared to the chip. Hard disks, after all, are mechanical. An access arm moves back and forth like a jackhammer over spinning platters. Contrast this jackhammer and turntable architecture with the electron movement inside a memory chip, and you realize there will come a time when solid state devices obsolete all mechanical storage devices.
It is already happening. Millions of digital music players use solid state flash drives, and they are increasingly an option for laptops. In datacenters, large solid state drives are slowly replacing banks of hard disks. It is only a matter of time. By 2025, the hard disk may be a memory, or better said, a "hard disk may be memory!"
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