Researchers from North Carolina State University have developed a new device that represents a significant advance for computer memory, making large-scale "server farms" more energy efficient and allowing computers to start more quickly.
Traditionally, there are two types of computer memory devices. Slow
memory devices are used in persistent data storage technologies such
as flash drives. They allow us to save information for extended
periods of time, and are therefore called nonvolatile devices. Fast
memory devices allow our computers to operate quickly, but aren't
able to save data when the computers are turned off. The necessity
for a constant source of power makes them volatile devices.
But now a research team from NC State has developed a single
"unified" device that can perform both volatile and nonvolatile
memory operation and may 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 NC State and co-author of a paper describing the
research. "Our device is called a double floating-gate field effect
transistor (FET). 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."
The double floating-gate FET could have a significant impact on a
number of computer problems. For example, it would allow computers to
start immediately, because the computer wouldn?t have to retrieve
start-up data from its hard drive ? the data could be stored in its
The new device would also allow "power proportional computing." For
example, Web server farms, such as those used by Google, consume an
enormous amount of power - even when there are low levels of user
activity - in part because the server farms can?t turn off the power
without affecting their 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
Franzon also notes that the research team has investigated questions
about this technology's reliability, and that they think the device
"can have a very long lifetime, when it comes to storing data in the