3 ms·

the probability of having at least one bit error in 4 gigabytes of memory at sea level on planet Earth in 72 hours is over 95% . This metric is only relevant i

the probability of having at least one bit error in 4 gigabytes of memory at sea level on planet Earth in 72 hours is over 95% . This metric is only relevant if you read all 4 GB of your memory every second and use the data for something that can't stand a flipped bit. Then you'll have one problem for every 72 hours of constant use of all of your memory. How much of your memory do you use on average? How many flipped bits will be read, before being overwritten? How many bit flips cause a real problem? If one of the gray background dots of HN turns blue, I don't really care. The likelihood of an actual problem for an average user is vastly lower because of these factors. The average comment on the blog of this guy and on Reddit is just sad: it's all fine and well that anecdotal evidence and the Google paper tell you he's wrong, but his math makes sense. Doesn't anyone feel the need to get to the root of the error in his assertion?

mfukar 17y ago
The "metric" is always relevant. Your confusion comes from the fact that you're thinking about whether those errors are reflected in a user's experience. If you think about the concept of RAM coupled with the fact that desktops are most likely running every little piece of software available (OS, a browser with several windows/tabs open, IM programs, a game, etc.) you'll see why this is a big deal. And let's not even mention servers and machines where actually significant work is being carried out..
- Confusion 17y ago
  I'm responsible for a handful of servers where 'actually significant work' is being carried out. My reasoning applies to those machines just as much: - how much memory is in use? - how large is the chance that a flipped bit is read (as opposed to being overwritten before being read)? - What are the consequences of the flipped bit? Apart from that: there are quite a few desktops in the world where 'actually significant work' is being carried out.
  - regularfry 17y ago
    The author touches on the "how much memory is in use" question: all major OSes use unallocated RAM as a file cache (or equivalent), so no matter where the error happens, it is almost certain to hit something. Whether that "something" is actually relevant is another matter.
  - mfukar 17y ago
    Those are not directly related questions; the answer to each of those depends on the setup of the machine, both on hardware and software, and the practical cases are far too many to enumerate on a single blog post. You are welcome to perform some tests or even theorycrafting on your systems. On an unrelated note, I did not mean to demean desktops, but the reality is that there's orders of magnitude more devices that carry out tasks more critical than image processing or development. Embedded devices are one example.

mfukar 17y ago

The "metric" is always relevant. Your confusion comes from the fact that you're thinking about whether those errors are reflected in a user's experience. If you think about the concept of RAM coupled with the fact that desktops are most likely running every little piece of software available (OS, a browser with several windows/tabs open, IM programs, a game, etc.) you'll see why this is a big deal. And let's not even mention servers and machines where actually significant work is being carried out..

Confusion 17y ago
I'm responsible for a handful of servers where 'actually significant work' is being carried out. My reasoning applies to those machines just as much: - how much memory is in use? - how large is the chance that a flipped bit is read (as opposed to being overwritten before being read)? - What are the consequences of the flipped bit? Apart from that: there are quite a few desktops in the world where 'actually significant work' is being carried out.
- regularfry 17y ago
  The author touches on the "how much memory is in use" question: all major OSes use unallocated RAM as a file cache (or equivalent), so no matter where the error happens, it is almost certain to hit something. Whether that "something" is actually relevant is another matter.
- mfukar 17y ago
  Those are not directly related questions; the answer to each of those depends on the setup of the machine, both on hardware and software, and the practical cases are far too many to enumerate on a single blog post. You are welcome to perform some tests or even theorycrafting on your systems. On an unrelated note, I did not mean to demean desktops, but the reality is that there's orders of magnitude more devices that carry out tasks more critical than image processing or development. Embedded devices are one example.