Computer chips in development at the University of Wisconsin–Madison could make future computers more efficient and powerful by combining tasks usually kept separate by design.
Jing Li, assistant professor of electrical and computer engineering, is creating chips that can be configured to perform complex calculations and store massive amounts of information within the same integrated unit—and communicate efficiently with other chips. She calls them “liquid silicon.”
“Liquid means software and silicon means hardware. It is a collaborative software/hardware technique,” says Li. “We want to target a lot of very interesting and data-intensive applications, including facial or voice recognition, natural language processing and graph analytics.”
The high-speed number crunching of processors and the data warehousing of big storage memory in computers usually fall to two different types of hardware.
Processor and memory chips typically are separately produced by different manufacturing foundries, then assembled by system engineers on printed circuit boards to make computers and smartphones.
The separation means even simple operations, like searches, require multiple steps to accomplish: first fetching data from the memory, then sending that data through the deep storage hierarchy to the processor core.
The chips Li is developing incorporate memory, computation, and communication into the same device. It does this using a layered design called monolithic 3-D integration: silicon and semiconductor circuitry on the bottom connected with solid-state memory arrays on the top using dense metal-to-metal links. End users will be able to configure the devices to allocate more or fewer resources to memory or computation, depending on which types of applications a system needs to run.
To help harness the new chip’s potential, Li’s group is also developing software that translates popular programming languages into the chip’s machine code, a process called compilation. Programmers will be able to port their applications directly onto the new type of hardware without changing their coding habits.
To evaluate the performance of the prototype liquid silicon chips, Li and her students established an automated testing system to reveal reliability problems.