Old people live longer?
From Ars Technica
An analysis of 2,007 damaged or defective hard disk drives (HDDs) has led a data recovery firm to conclude that “in general, old drives seem more durable and resilient than new drives.”
If you go out and lo0k at human deaths over a period of years, you will also find that Baby Boomers are much more likely die over age 70 than Gen X, and Gen X are more likely to die after 50 than millennials. It’s too late for Boomers to die young.
Going on, we see that
backup and cloud storage company Backblaze uses hard drives that surpass the average life span Secure Data Recovery saw among the HDDs clients sent it last year. At the end of 2022, Backblaze’s 230,921 hard drives had an average age of 3.6 years versus the 2-year, 10-month average time before failure among the drives Secure Data Recovery worked on last year.
Again, if you look at an older group of people, the average age at death will be older than if you use a younger group.
This all wouldn’t matter so much, except that they are also trying to draw conclusions about novel disk drive technologies being less reliable. There are statistical techniques to account for the different follow-up time of different groups of drives, but it’s quite possible those techniques would just tell you “nope, too soon to tell”.
Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »
Something similar happens with tech infrastructure like submarine communications cables.
When a cable is built, engineers will say it has an expected lifespan of 25 years. Then 15 years on, the same cable might have an expected lifespan of another 18 years. And so on.
12 months ago
When I was born in NZ my life expectancy was 69.7 years, an age I’m yet to reach. However the good news is that if I was born this year my life expectancy would be now 82.8 yrs.
From cohort Life tables Im *expected* to live longer than that of course, another 17 years
12 months ago
Are they talking about age at failure or how many more years they last. By my reading it one possibility is that there might be a high failure rate at early years.
For example, if a newborn has a 50% chance of dying in their first year (age 0) and 50% chance at 80 then life expectancy at birth is 40 years. But life expectancy at age 1 is (a further) 79 years which is longer at an older age. Isn’t this what they are describing?
12 months ago