In the early days, stan­dard com­puters could be as large as a single story house. Over the last sev­eral decades, many devel­op­ment efforts have focused on shrinking them for use in the home and even­tu­ally any­where in the world — on the train, in a cave, you name it.

That is, if you want to use stan­dard computer-​​based tools, like the Internet or iTunes. Today’s tiny devices are capable of crunching lots of data pretty quickly, but what if “lots of data” means tens or hun­dreds of ter­abytes or more, amounts that would take a typ­ical PC days or weeks to process? For that we need super­com­puters, which are still big and expensive.

Peter Des­onyers, assis­tant pro­fessor in the Col­lege of Com­puter and Infor­ma­tion Sci­ence, recently received a CAREER award from the National Sci­ence Foun­da­tion to explore solid-​​state drives, which are data-​​storage devices that use flash memory, as new com­pu­ta­tional tools. If suc­cessful, these devices could rev­o­lu­tionize the industry by making large-​​scale com­pu­ta­tion pos­sible for the masses.

Flash was orig­i­nally designed to replace hard drives as a faster data-​​storage method. “It is some­what faster for large files than hard drives,” Desnoyers said. But more impor­tant, it is “far more nimble, able to switch from one small file to another at elec­tronic speeds while a hard drive must wait for mechan­ical parts to move.”

The only problem is flash came too late. Over the last sev­eral decades, com­puter sci­en­tists have opti­mized soft­ware to run on hard drives. Any­thing that would run better on flash has not yet been designed. “We’ve stopped trying to do any­thing that involves com­plex data struc­tures out­side of the computer’s memory,” Desnoyers said. “We’ve stopped trying to do the things that flash is best at.”

Before com­puter sci­en­tists can start designing new uses for flash they must first under­stand how it behaves. In par­tic­ular, Desnoyers’ team is looking at frag­men­ta­tion, in which cre­ating and deleting files over time causes a storage system to become ran­domly arranged.

Hard drives, Desnoyers explained, slow down but con­tinue to work as they become frag­mented. But flash must con­stantly defrag­ment in order to work at all. It must con­stantly rearrange blocks of data like a sliding tiles puzzle, shuf­fling it between unoc­cu­pied areas in order to clear more space. This process causes the drive to run slower and even­tu­ally reduces its lifetime.

We’re trying to under­stand it so we can design better algo­rithms to deal with it,” Desnoyers said.

In addi­tion to making per­sonal com­puters more pow­erful, solid-​​state storage devices could also extend the power of super­com­puters beyond their cur­rent capacity. Desnoyers’ team is working with Oak Ridge National Lab­o­ra­to­ries to explore ways of making that possible.

Still, Desnoyers isn’t con­vinced that flash is the future of com­puting. “Disk is get­ting bigger and cheaper faster than flash is,” he said. “For flash to become really wide­spread, we need to develop new approaches to make it worth the price — it has to enable us to do things with com­puters that we couldn’t do before.”