Robert H. Dennard, an engineer who invented the silicon reminiscence expertise that performs an indispensable position in each smartphone, laptop computer and pill pc, died on April 23 in Sleepy Hole, N.Y. He was 91.
The reason for dying, at a hospital, was a bacterial an infection, mentioned his daughter, Holly Dennard.
Mr. Dennard’s pioneering work started at IBM within the Nineteen Sixties, when the tools to carry and retailer pc information was costly, hulking — usually room-size machines — and gradual. He was learning the rising area of microelectronics, which used silicon-based transistors to retailer digital bits of knowledge.
In 1966, Mr. Dennard invented a technique to retailer one digital bit on one transistor — a expertise known as dynamic random-access reminiscence, or DRAM, which holds the knowledge as {an electrical} cost that slowly fades over time and have to be refreshed periodically.
His discovery opened the door to beforehand unimaginable enchancment in information capability, with decrease prices and better speeds all utilizing tiny silicon chips.
DRAM has been the premise of regular progress within the many years since. Excessive-speed, high-capacity reminiscence chips maintain and shortly shuttle information to a pc’s microprocessor, which converts it into textual content, sound and pictures. Streaming movies on YouTube, enjoying music on Spotify or Apple Music and utilizing A.I. chatbots like ChatGPT depend upon them.
“DRAM has made a lot of recent computing potential,” mentioned John Hennessy, chair of Alphabet, Google’s mum or dad firm.
Mr. Dennard additionally devised an idea that has served as a highway map for future advances in microelectronics. Debuted in an preliminary paper in 1972, and fleshed out in one other two years later, he described the physics that might permit transistors to shrink and develop into extra highly effective and more cost effective, even because the vitality each consumed would stay nearly fixed.
The precept, often called Dennard scaling, was complementary to a prediction made in 1965 by Gordon Moore, who went on to co-found Intel. Mr. Moore claimed that the variety of transistors that could possibly be crammed onto a silicon chip could possibly be doubled about each two years — and that computing energy and speeds would speed up on that trajectory. His prediction grew to become often called Moore’s Legislation.
Moore’s Legislation involved the density of transistors on a chip, whereas Dennard scaling primarily involved energy consumption, and by 2005, it reached its limits: Transistors had develop into so tiny, they started to leak electrons, inflicting chips to warmth up and devour extra vitality.
However Mr. Dennard’s method to figuring out challenges within the expertise, researchers say, has had an enduring impression on chip growth.
“All people in semiconductors studied his rules to get the place we’re as we speak,” mentioned Lisa Su, chief govt of Superior Micro Gadgets, a big chipmaker, and a former colleague of Mr. Dennard’s at IBM.
Robert Dennard was born on Sept. 5, 1932, in Terrell, Texas, the youngest of 4 kids. His father, Buford Dennard, was a dairy farmer, and his mom, Loma Dennard, was a homemaker who additionally labored in a college cafeteria.
The household moved east when Robert was a small little one, and he started his schooling in a one-room schoolhouse close to Carthage, Texas. The household later moved to Irving, then a small city, when his father acquired a job with a fertilizer firm there.
Rising up, Robert developed an appreciation for the humanities, studying the H.G. Wells tales and Ogden Nash poems that his oldest sister, Evangeline, had left behind when she departed Texas to be an Military nurse throughout World Struggle II. In an oral historical past interview for the Laptop Historical past Museum in 2009, he recalled listening numerous instances to an album of Sigmund Romberg operettas. “She left me behind some actually good issues to start out off some type of mental profession,” he mentioned of his sister.
In highschool, he was a very good scholar, particularly in math and English, and had deliberate to go to a close-by junior faculty. However his aptitude for music provided a unique path. He performed the E-flat bass in his highschool band, and when the director of the Southern Methodist College band visited, he provided Robert a scholarship.
“That was my alternative,” Mr. Dennard recalled.
Although music was his entry level, he earned undergraduate and grasp’s levels in electrical engineering on the college. He later acquired a Ph.D. from the Carnegie Institute of Expertise, now Carnegie Mellon College.
In 1958, Mr. Dennard was employed by IBM, the place he spent his complete profession till retiring in 2014.
He was married 3 times. He and his second spouse, Mary Dolores (Macewitz) Dennard, divorced in 1984, and in 1995 he married Frances Jane Bridges.
Along with his daughter and his spouse, Mr. Dennard is survived by one other daughter, Amy Dennard, and 4 grandchildren. His son, Robert H. Dennard Jr., died in 1998.
Over his profession, Mr. Dennard produced 75 patents and acquired a number of scientific awards, together with the Nationwide Medal of Expertise from President Ronald Reagan in 1988 and the Kyoto Prize in superior expertise from the Inamori Basis, in Japan, in 2019.
Within the 2009 interview, when Mr. Dennard was requested what recommendation he would give a teen involved in science and expertise, he pointed to his personal “very humble upbringing” and mentioned “anyone can take part on this.”
“There’s alternative there,” he mentioned. “These items don’t occur by themselves. It takes actual folks, making these breakthroughs.”
