The RISC-V-Based LightPC Keeps on Calculating No Matter How Many Times You Pull the Plug

Researchers from the Korea Advanced Institute of Science and Technology (KAIST) have developed a personal computer with a difference, and it's not just the result of using a RISC-V processor: The Lightweight Persistent Centric System, or LightPC, is built using only non-volatile memory, making it immune to power failures.

Traditional computing devices, from microcontrollers all the way up to mainframes and supercomputers, are built using a mixture of volatile memory like DRAM and non-volatile memory like SSDs. Non-volatile memory is fast, but if the power is cut before its contents can be written to non-volatile memory it's gone for good.

LightPC is different. Built around a custom eight-core RISC-V processor, there's no volatile memory in the system at all. Instead, all memory is non-volatile — provided using six open-channel persistent memory (OC-PMEM) modules. Using a variety of techniques including increased parallelism, the non-volatile memory approaches the performance of its volatile equivalent, the team claims.

“We mounted non-volatile memory on a system board prototype and created an operating system to verify the effectiveness of LightPC," explains Myoungsoo Jung, professor at KAIST's CAMELab and project lead. The results are impressive: The device performed perfectly even when powered up and down part-way through execution, resuming without delay, and was able to provide eight times as much memory, execute the program over four times as quickly, and draw 73 per cent less power than a traditional equivalent.

Jung and colleagues believe the design is most applicable to data centers and high-performance computing platforms, though the promise of an ability to withstand power cuts and a big increase in efficiency could prove tempting for embedded systems should the design scale suitably.

The team's work is to be presented at the International Symposium on Computer Architecture (ISCA) 2022 in June.