You've got to hand it to IBM's engineers. They drag themselves into work after their company's 100th birthday party, and then promptly announce yet another seismic invention. This time it's a new kind of phase change memory (PCM) that reads and writes 100 times faster than flash, stays reliable for millions of write-cycles (as opposed to just thousands with flash), and is cheap enough to be used in anything from enterprise-level servers all the way down to mobile phones.
PCM is based on a special alloy that can be nudged into different physical states, or phases, by controlled bursts of electricity. In the past, the technology suffered from the tendency of one of the states to relax and increase its electrical resistance over time, leading to read errors. Another limitation was that each alloy cell could only store a single bit of data. But IBM employees burn through problems, not only is their latest variant more reliable, it can also store four data bits per cell, which means we can expect a data storage "paradigm shift" within the next five years.
As the Press Release says :
- Reliable multibit phase-change memory technology demonstrated
- Scientists achieved a 100 times performance increase in write latency compared to Flash.
- Enables a paradigm shift for enterprise IT and storage systems, including cloud computing by 2016.
ZURICH, June 30, 2011 – For the first time, scientists at IBM Research have demonstrated that a relatively new memory technology, known as phase-change memory (PCM). ( Now actually, PCM ( also known as Chalcogenide RAM and C-RAM) is a type of non-volatile computer memory. PRAMs exploit the unique behavior of chalcogenide glass. With the application of heat produced by the passage of an electric current, this material can be "switched" between two states, crystalline and amorphous. )
Unlike Flash, PCM is also very durable and can endure at least 10 million write cycles, compared to current enterprise-class Flash at 30,000 cycles or consumer-class Flash at 3,000 cycles. While 3,000 cycles will out live many consumer devices, 30,000 cycles are orders of magnitude too low to be suitable for enterprise applications
Here is some of the stuff regarding the 'inside' the technology (in which all are not interested), but as i am electronic engineer , i am kinda interested in it. So read further if you really want to know about the technology.
PCM leverages the resistance change that occurs in the material -- an alloy of various elements -- when it changes its phase from crystalline –featuring low resistance – to amorphous – featuring high resistance – to
store data bits. In a PCM cell, where a phase-change material is deposited between a top and a bottom electrode, phase change can controllably be induced by applying voltage or current pulses of different strengths. These heat up the material and when distinct temperature thresholds are reached cause the material to change from crystalline to amorphous or vice versa.
In addition, depending on the voltage, more or less material between the electrodes will undergo a phase change, which directly affects the cell's resistance. Scientists exploit that aspect to store not only one bit, but multiple bits per cell. In the present work, IBM scientists used four distinct resistance levels to store the bit combinations "00", "01" 10" and "11".
Using that technique, the IBM scientists were able to mitigate drift and demonstrate long- term retention of bits stored in a subarray of 200,000 cells of their PCM test chip, fabricated in 90-nanometer CMOS technology.