Fernbach studied physics at Temple University with a Master 's degree in 1952 and his doctorate at the University of California, Berkeley. Then he went to the Lawrence Livermore National Laboratory ( LLNL ), where he in 1955 head of the computer department was. 1958/59 he also directed the theory department. From 1975 until his retirement in 1979, he was Deputy Associate Director for Scientific Support LLNL. After that, he was a consultant, including for Control Data.
Fernbach played a major role in the development of supercomputers for scientific purposes in the U.S., starting with the UNIVAC I and later especially with Control Data and Cray (especially in contact with Seymour Cray ). He was a member of many government committees at the National Academy of Sciences and the National Science Foundation. In 1974 he founded a supercomputer data center for nuclear fusion, later the National Energy Research Supercomputer Center ( NERSC ). He was chairman of the IEEE sub - committees for scientific supercomputers and founded the annual meeting Compcon the IEEE Computer Society.
He was a Fellow of the American Physical Society and the American Association for the Advancement of Science. He was also editor of the series Methods in Computational Physics and the Journal of Computational Physics and oversaw the division of the Journal of Supercomputing Applications.
In 1987 he received the W. Wallace McDowell Award.