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Comment by pedrocr | Hacker News Reader

It would be awesome if companies like Google would calculate MTBF statistics on components. They've done it for disks and it would be great to extend it to CPUs and memory modules. They're probably in a better position than even Intel to calculate these things with precision.

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Here's one for RAM in servers, from Google: http://news.cnet.com/8301-30685_3-10370026-264.html

Found it here, which also goes into some testing the Guild Wars guys did on their population of gamer PCs: http://www.codeofhonor.com/blog/whose-bug-is-this-anyway (scroll down to "Your computer is broken", around 1% of the systems they tested failed a CPU-to-RAM consistency stress test)

Both of them indicate intermittently defective components in running systems are way more common than anybody assumes.

This is very interesting

But when they say "Memory Error", even though it's something detected/corrected by ECC I'm not sure we can say 'the memory is defective'

It may be a combination of the conditions of power/load/data/time since last refresh and variance between modules.

Since Google appears not to show all the data they have, we probably are not going to get that from them though :/

They'd have to be careful with how they quoted the numbers though. As Linus accurately points out, MTBF varies wildly depending on the usage pattern. If you want to quote it in a unit of time, e.g. "years", then you have to specify the usage the part has been under, which will be very different for a server part compared to a desktop part. You could quote it per instruction or equivalent, I suppose, taking into account how hard the component is used, but even that isn't perfect.

MTBF is quite well tied to a contract purchasing when you buy large quantities of components for manufacturing. Intel don't know where people are going to use their products and the range of environments they get exposed to can't be easily equated for.

I know Intel has been working for some time on the idea of high temperature data centres, this will impact the MTBF of all components but you can always calculate the cost of the losses vs the cost of the cooling: http://www.datacenterdynamics.com/focus/archive/2012/08/inte...

Interesting relevant paper: http://www.cs.cmu.edu/~bianca/fast07.pdf

Table 3 suggests that there are data sets that include all components (CPU, memory, power supplies, etc.).

Data of the sort shown in Table 3 certainly exists. However, it's often inaccessible to the public because companies tend to treat it as a trade secret.

Any large company that makes things employs a bunch of reliability engineers, who are usually EE's or ME's who make Weibull plots and bathtub curves all day (to set the warranty duration, mostly). These guys have all the data you could ever want on this topic, but they're not sharing. Especially at Intel.

I'm almost sure that the components without moving parts will become technologically obsolete long before they start to fail. When I buy used laptop I always change the HDD, the DVD and its reliability jumps sharply up.

Even things with moving parts, it would be nice to know that model X of brand Y has a MTBF of 4.5 years, but hunting the same model X 4.5 years later isn't likely to yield the exact same hardware but some later revision of the same specced hardware.

That may very well be true on average but I'd bet there are plenty of CPUs and memory modules that fail in the first year of usage for example. After all CPUs are tested and sorted into high/low performance parts, so sample variation itself would be enough to generate some early failures.

As a consumer it's hard enough to keep up with what's reliable in hard drives. Keeping the manufacturers honest with good stats for the most common parts would be great.

I've seen a lot of failed laptop motherboards.

They might very well do this already. But it'd seem they're disincentivized to make this information public... do they publish the disk information?

They've published some stuff on disks:

https://static.googleusercontent.com/external_content/untrus...

The backblaze guys also have a big data set:

http://blog.backblaze.com/2013/11/12/how-long-do-disk-drives...

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