A peek at new memory technologies

Researchers are working on several alternate technologies that could eventually replace those in the three memory types commonly used today: low-cost Dynamic RAM (DRAM) used in PCs and servers; fast Static RAM (SRAM) used for processor caches and mobile devices; and non-volatile flash memory, used in everything from computer BIOSs to cell phones. Here are some of them.

Researchers at IBM, Intel and other companies envision the development of a universal memory technology that could someday replace all three. For example, non-volatile RAM could allow computers to boot up and power down instantly because stored information wouldn’t be lost when power switches off. That said, the emergence of a universal memory technology is probably at least 10 to 15 years away.

Ferro-electric RAM (FRAM) and Magneto-resistive RAM (MRAM) are the best-funded and most-evolved among emerging memory technologies. FRAM is a non-volatile RAM that was developed by Ramtron International. It’s licenced by Texas Instruments and others. More than 30 million products have already shipped using FRAM, including metering, radio frequency identification and smart-card devices, according to Ramtron.

FRAM, which is based on nanoscale ‘quantum dots,’ uses less power and writes faster than DRAM or flash, and it has a long life span. The technology remains 20 to 50 times more expensive per bit than DRAM, and chip density is far lower. Ramtron is prototyping 1 MB parts today, and hopes to push the technology to 4 MB or 8 MB in 2006. Until MRAM is ready for the market, however, FRAM is the only game in town for non-volatile DRAM.

Phase-change memory (PCM) is a fast, non-volatile memory that proponents claim could become a universal memory. IBM and Intel have each partnered with other companies to develop the technology. While PCM technology is much faster than flash, it’s slower than SRAM. To be competitive with DRAM, it would also have to support unlimited writes. IBM’s research shows that PCM can match flash’s 100,000-write limit, but endurance beyond that hasn’t been proved.