Accession Number : AD0777166

Title :   A Comparison of Fault-Tolerant and Externally Redundant Computers,


Personal Author(s) : Hecht,H.

Report Date : 25 JAN 1974

Pagination or Media Count : 42

Abstract : The reliability of fault-tolerant and externally redundant computers is compared with reference to long-duration space missions. Technology, computer performance, and reliability assumptions are equal for all configurations. It is then found that the postulated fault-tolerant computer requires about four times the resources of an equivalent simplex design. An active and spares configuration and a voting configuration of four simplex computers are compared to the fault-tolerant computer. For mission durations of three years or longer the fault-tolerant design has a significant reliability advantage. For five-year missions the reliabilities are as follows: Fault-tolerant 0.9530, Active and spares 0.4920, Voting 0.1918. (Author)

Descriptors :   *Computers, *Reliability(Electronics), Space missions, Redundant components, Mathematical logic, Modules(Electronics)

Subject Categories : Computer Hardware
      Mfg & Industrial Eng & Control of Product Sys

Distribution Statement : APPROVED FOR PUBLIC RELEASE