Radioactive decays and cosmic particles flipping bits give an upper bound for reliability. You are not going to see low-background packages and rad-hard chips in your iPhone.
If it works 99.9999999999%, then it has a failure rate of 0.0000000001%, or 1E-12. Considering that a modern CPU executes approximately 1E9 operations per second, and that regular HDDs have a worse-case BER of 1 in 1E14 bits, 1E-12 is actually rather horrible and the actual error rate of computer hardware is much better than that.
Imagine if a CPU calculated 1+1=3 every 1E12 instructions. At current clock rates, that's a fraction of an hour. Computers simply would not work if CPUs had such an error rate.
I picked the 1E-12 number arbitrarily, but it's quite illustrative of the reliability computers are expected to have, despite their flaws.
Amazon is hosting life-safety applications in EC2. Commodity x86 hardware is grossly negligent for that environment.
Of course, you’ll also find a tendency there towards specified hardware. They bend or break it to use COTS x86 machines, but—as I think I heard from a comment here last week—nearly nobody ever specified wanting AMT in the initial design, so it’s pretty weird that we’re all buying and deploying it.
I wonder if home systems are equally vulnerable, or if there is something about data center system design or facilities that make them more susceptible?
I ask because I had a couple of home desktop Linux boxes once, without ECC RAM, that were running as lightly loaded servers. I ran a background process on both that just allocated a big memory buffer, wrote a pattern into it, and then cycled through it verifying that the pattern was still there.
Based on the error rates I'd seen published, I expect to see a few flipped bits over the year (if I recall correctly) that I ran these, but I didn't catch a single one.
Later, I bought a 2008 Mac Pro for home, and 2009 Mac Pro for work (I didn't like the PC the office supplied), and used both of those to mid 2017. They had ECC memory, and I never saw any report when I checked memory status that they had ever actually had to correct anything.
So...what's the deal here? What do I need to do to see a bit flip from radiocative decay or cosmic rays on my own computer?
Personal machines are typically limited by what your senses can handle. There are few of them for starters. They idle a lot. If many pieces failed inexplicably it's not likely to be something you are personally paying attention to with your senses.
(I have personally observed ram and disk failures on personal machines anyway. And I have seen stuff in my dmesg indicating hardware faults on my personal desktops, but rarely in a way that I notice in actual use not looking at dmesg.)
I was told once that today's concrete has a much higher background radiation than brick and mortar from before the 50s. There is also more steel in data centres.
However, I'm not at all sure if background radiation of building materials is even in the right order of magnitude to matter here. Probably not.
The reason the modern stuff is more radioactive is the massive number of atmospheric nuclear weapons tests conducted starting in 1945. I imagine the concrete has the same issue.
This is what I read online. A typical hardware components is enclosed in a aluminum case so really gamma radiation is of concern right?
I don't know if the sort of radiation they give out is of much risk to computers however.
This isn't a probability question. I don't understand why it's being discussed as if it were.
The fact that DRAM older than a few years is effectively immune to RH suggests it is possible to manufacture such. Yes, it will cost more, but I think many would be willing to pay for it like they used to, for none other than the assurance of having more reliable memory.
https://arstechnica.com/information-technology/2016/03/once-...
ECC helps, and can be done at full rate, but isn't a complete solution for all possible problems. And anything you do in hardware at full RAM speed is expensive.
Also, DDR3/4 DRAM is glacially slow in latency terms, it's far from clear that there would be appreciable slowdown. There are already big latency compromises in the standardized JEDEC protocols that are not inherent in DRAM - it would be very two-faced for DRAM vendors to say they'll only trade off latency over backward compatibility or tiny cost savings, but not over correctness.
There are many types of users and some don't care if it fails in a blue moon. Hell 99% might be good enough if the price was right.