IBM Teases Storage Memory Breakthrough

IBM researchers studying a new digital memory technology have figured out how to store three times the number of bits per cell than was previously possible, the company announced today.

The discovery could pave the way for critical computing platforms like databases and operating systems to use phase-change memory (PCM), which has higher speeds and more density than other memory technologies on the market today.

Researchers previously managed to store 1 bit (a digital "0" or "1") per PCM cell. IBM's breakthrough, announced today at the IEEE International Memory Workshop in Paris, allowed it to successfully store three bits per cell in a 64k-cell PCM array at elevated temperatures and after a million endurance cycles.

"Phase change memory is the first instantiation of a universal memory with properties of both DRAM and flash, thus answering one of the grand challenges of our industry," Haris Pozidis, an IBM researcher, said in a statement. "Reaching three bits per cell is a significant milestone because at this density the cost of PCM will be significantly less than DRAM and closer to flash."

Like DRAM and SRAM memory, any PCM byte can be written, whereas flash requires an entire block to be written. That principle, in addition to the floating gate architecture of a flash cell, means reducing its size negatively affects its performance. However, the smaller the PCM cell, the denser and faster the chip becomes. In addition, PCM handles millions of rewrites compared to hundreds of thousands for flash.

IBM envisions PCM being used in tandem with DRAM and flash-based storage, similar to how hybrid drives work today. In mobile devices, the operating system would be stored on the PCM unit, enabling it to boot up in a few seconds, while the rest of the storage would be flash-based.