[brookst]

The 200,000 figure isn't super meaningful unless they report average folds to failure and standard deviation.

From that article, it could be that they test to 200,000 folds because at that point 99.6% have failed, and the 50% failure rate might be at 100,000. Or 20,000. Or 190,000.

I don't think they're saying that 100% of phones will last to 200,000 folds. That would be a bold claim indeed.

[dr_kiszonka]

My interpretation of this article and the original press release is that the screens are supposed to last at least 200k folds.

[brookst]

If it's 0% failure at 200k folds, that means the 200k is about six standard deviations away from the mean, so I think (statistics gurus please correct) that says the average device will last for 1.7m folds.

[DrBenCarson]

That can’t be accurate just anecdotally. More likely they call it or or two sds out and chalk up the remaining 10 or so percent as RMAs.

You’re also assuming a normal distribution. This very well might not be a normal distribution

[brookst]

Product lifetime is generally modeled using the Weibull distribution[1]. Depending on the parameters, a normal distribution is a reasonable approximation. Without data on the parameters, and just discussing whether "tested to 200,000 folds" means that every device will survive 200k folds, I think it's fair to use a normal distribution.

Agreed that they probably expect some percentage of RMAs. In fact, I'd argue that "tested to 200k folds" means that 200k gets them enough failures to model the lifetime distribution, so the average lifetime is probably considerably less than 200k.

1. https://www.weibull.com/basics/lifedata.htm

[pfannkuchen]

Is it valid to assume a normal distribution here?