Failure numbers every programmer should know

Peter Norvig’s “Latency Numbers Every Programmer Should Know” are a classic in software engineer training. The original sixteen numbers represent, for programmers, the hard constraints of our hardware. In the early 2000s, if you cared about writing fast code you knew that a disk seek cost about 10 milliseconds. “You don’t have to be an engineer to be a racing driver, but you do have to have Mechanical Sympathy.” Latency numbers are for programmers who want their systems to be fast. Failure numbers are for programmers who want their systems to be reliable. Show chart Thing Type MTTF (years) AFR Notes CPU failure Hardware ~1,700 ~0.06% Server CPUs very rarely fail outright. Intel IT measured a 0.06% CPU AFR across 223,050 CPUs in 207,956 HPC servers, which converts to an MTTF of roughly 1,700 years by the simple reciprocal math used here.1 Motherboard failure Hardware ~260 ~0.38% Motherboards are still rare failures, but less rare than CPUs. In the same Intel IT dataset, motherboards…