Bits Flip: How something so miniscule can pose a huge hazard


A quick one, since I should already be in bed:
The latest Veritasium video talks about a problem with computers that we can’t eliminate: bit flips caused by cosmic rays and interstellar particles.  You would think it would be impossible to detect a single bit flip in 64 bit computers with gigabytes of RAM, but he cites several provable examples, some which people have been recorded and documented.  (One of them proving why electronic voting is a bad idea and should always be done on paper ballots.)
There is another way bit flips can happen.  Bits in a computer are not actually “on and off”, charged or no charge.  They’re high and low states of charge, and if an improper charge is in between, a bit can be interpreted as on, off or both.

 

Comments

  1. JM says

    There is already a solution to this problem, it just isn’t widely used. Error correction code memory can detect single bit flips and correct for it.

    It isn’t more widely used on small computers for reasons that are more marketing then anything. Widespread use would increase costs for memory slightly. The real reason it isn’t used more is that computer companies have long divided the market into high end and everyday computing. ECC memory is reserved for high end systems at inflated prices.

    • says

      I read about that. NASA’s solution was multiple computers on board Apollo and other rockets and majority vote. Now use specialized and battle hardened 1990s computer chips to avoid it.

      The video goes on to explain the Intel chip problem in the US, how they built a factory too near a radioactive source and their chips produced a lot of errors. Oops.

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