statistics - 宇宙射线 : what is the probability they will affect a program?

Question

我再次进行设计审查，遇到了这样的说法:特定场景的概率“小于宇宙射线影响程序的风险”，我突然想到，我没有最微弱的风险知道这个概率是多少。

"Since 2^-128 is 1 out of 340282366920938463463374607431768211456, I think we're justified in taking our chances here, even if these computations are off by a factor of a few billion... We're way more at risk for cosmic rays to screw us up, I believe."

这个程序员正确吗？宇宙射线击中计算机并影响程序执行的概率是多少？

Answer 1

来自Wikipedia :

Studies by IBM in the 1990s suggest that computers typically experience about one cosmic-ray-induced error per 256 megabytes of RAM per month.^[15]

这意味着每月每字节的概率为 3.7 × 10^-9，或每秒每字节的概率为 1.4 × 10^-15。如果你的程序运行了1分钟，占用了20MB的RAM，那么失败的概率是

                 60 × 20 × 1024²
1 - (1 - 1.4e-15)                = 1.8e-6 a.k.a. "5 nines"

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错误检查有助于减少失败的后果。另外，正如 Joe 所说，由于芯片尺寸更加紧凑，故障率可能与 20 年前有所不同。