Robert H. Dennard, an engineer who invented the silicon reminiscence expertise that performs an indispensable function in each smartphone, laptop computer and pill laptop, died on April 23 in Sleepy Hole, N.Y. He was 91.
The reason for loss of life, at a hospital, was a bacterial an infection, stated his daughter, Holly Dennard.
Mr. Dennard’s pioneering work started at IBM within the Sixties, when the gear to carry and retailer laptop knowledge was costly, hulking — typically room-size machines — and sluggish. He was learning the rising discipline of microelectronics, which used silicon-based transistors to retailer digital bits of knowledge.
In 1966, Mr. Dennard invented a approach to retailer one digital bit on one transistor — a expertise referred to 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 knowledge 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 knowledge to a pc’s microprocessor, which converts it into textual content, sound and pictures. Streaming movies on YouTube, taking part in music on Spotify or Apple Music and utilizing A.I. chatbots like ChatGPT rely upon them.
“DRAM has made a lot of contemporary computing potential,” stated John Hennessy, chair of Alphabet, Google’s father or mother 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 will enable transistors to shrink and develop into extra highly effective and more cost effective, even because the vitality every one consumed would stay virtually fixed.
The precept, generally known as 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 turned generally known as 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 eat extra vitality.
However Mr. Dennard’s method to figuring out challenges within the expertise, researchers say, has had a long-lasting impression on chip growth.
“All people in semiconductors studied his ideas to get the place we’re right this moment,” stated Lisa Su, chief govt of Superior Micro Units, 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 baby, 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 obtained 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 Conflict II. In an oral historical past interview for the Pc 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 begin off some form of mental profession,” he stated of his sister.
In highschool, he was an excellent scholar, particularly in math and English, and had deliberate to go to a close-by junior school. However his aptitude for music provided a special 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 Know-how, 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 Know-how 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 youngster fascinated with science and expertise, he pointed to his personal “very humble upbringing” and stated “anyone can take part on this.”
“There’s alternative there,” he stated. “This stuff don’t occur by themselves. It takes actual folks, making these breakthroughs.”
