Is the clock already ticking on flash memory?

Just as the enterprise is finally ready to take advantage of the faster throughput and lower power usage of flash-based solid state technology, along comes another entrant to the cutting-edge storage market known as phase-change memory (PCM).

Intel and PCM booster Numonyx -- which is actually a joint venture between Intel and STMicroelectronics -- recently claimed a breakthrough in PCM technology that overcomes one of the chief limitations of the technology -- the inability to pack a multitude of memory cells onto a single die in order the attain sufficient memory. The companies say they have figured out a way to place the cells on top of each other without breaking down the delicate structure that gives the technology its write/erase advantages and bit-alter capabilities.

Like CDs and DVDs, PCM relies on a material called chalcogenide that has the ability to become more ordered and less reflective when heated by a laser. This allows electrical signals to be overwritten without the erase cycle required by flash technology. PCM also allows data to be read directly from the drive, rather than having it shuttled to RAM first. So it's no wonder PCM offers both better throughput and faster access.

The new Intel/Numonyx design adds a metal layer around the PCM memory cells within the chip that shields it from underlying silicon and allows multiple cells to be stacked on top of each other. They also developed a new kind of switch mechanism that improves on the phase-changing capabilities of the memory cell.

Numonyx has long claimed that PCM is a superior memory structure than anything seen before because it combines the best characteristics of NOR and NAND Flash, as well as RAM and EEPROM. Not only is it bit-alterable with improved read/write speeds, it is also non-volatile and offers better scalability factors due to the fact that it does not store actual electrons, just chalcogenides in different states. The company even claims that smaller structures will see continually improving performance.

Initial PCM deployments are likely a few years off, and even then most likely in cell phone and other handheld devices from Samsung and others. So there's no need to start second-guessing that new SSD array deployment just yet.

Still, the writing is going up on the wall fairly quickly, suggesting the even after all this fuss, today's SSD is only a flash in the pan.