Memory tech 'unifies' flash and DRAM

Scientists have developed a technology that could revolutionise the way that memory is used in computers by combining the speed of DRAM with the non-volatile properties of flash memory.

Researchers at the North Carolina State University have invented a device called a double floating-gate field effect transistor (FET) that is claimed to make all types of computers more energy efficient, from large scale server farms to mobile handsets, allowing machines to power down significantly faster.

Usually computer memory devices are split into two categories. Non-volatile devices are used in persistent data storage technologies such as flash drives which allow storage of information for longer periods of time.  Faster, volatile devices operate quickly but are unable to save data when switched off, requiring a constant source of power.

However the research team believes that they have found a way to incorporate the chararacteristics of both into one unified device that can be used in the main memory.

“We’ve invented a new device that may revolutionize computer memory,” says Dr. Paul Franzon, a professor of electrical and computer engineering at the university.

“Existing nonvolatile memory used in data storage devices utilizes a single floating gate, which stores charge in the floating gate to signify a 1 or 0 in the device – or one ‘bit’ of information. By using two floating gates, the device can store a bit in a nonvolatile mode, and/or it can store a bit in a fast, volatile mode – like the normal main memory on your computer.”

It is thought that the double floating-gate FET device will be able to allow computers to start significantly faster as the computer would not have to retrieve start up data from its hard drive, with the data being stored on its main memory.

Furthermore double floating-gate FET will help solve the problem of web server farms which consume massive amounts of power even when being used at low levels, mainly due to the fact that it is not possible to turn power off as it will affect the main memory.

“The double floating-gate FET would help solve this problem,” Franzon says, “because data could be stored quickly in nonvolatile memory – and retrieved just as quickly. This would allow portions of the server memory to be turned off during periods of low use without affecting performance.”

Franzon also said that the research team has been investigating the technology’s reliability, believing that the device “can have a very long lifetime, when it comes to storing data in the volatile mode.”