Making computers, mobile devices more energy-efficient

Adegbija is researching techniques for efficiently

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leveraging a material called spin-transfer torque random access memory, or STTRAM, as an alternative for static RAM in computer caches. STTRAM can store the same amount of data as static RAM using only one-quarter to one-ninth of the space, making it especially useful for resource-constrained devices like mobile phones and tablets.

Lower Energy Consumption is Key

While they reduce the time it takes to access and run programs on computer devices, caches increase power consumption, which makes them expensive. However, if carefully designed, they can also make computers more energy-efficient.

"If you reduce how much time you spend accessing data, you may also be expending less energy despite consuming more power," Adegbija said. "My research explores new ways to take advantage of the cache's positive qualities while mitigating its negative qualities."

Data for most programs only need to remain in the cachefor up to few hundred milliseconds, but STTRAM intrinsically retains data for much longer—up to 10 years. Adegbija's team has found that designing STTRAM caches to retain data for only as long as needed by each program can reduce energy consumption by up to 84%.

Their research focuses on designing STTRAM caches that can dynamically and automatically adapt to the needs of different running programs, thereby making resource-constrained devices more energy-efficient.

https://phys.org/news/2019-06-mobile-devices-energy-efficient.html