Re: how can a bit be off in memory?

Jean-David Beyer wrote:
Robert M. Riches Jr. wrote:
On 2007-06-29, Charles T. Smith <cts.private@xxxxxxxxx> wrote:
Vim started crashing on me, particularly when I tried to open new lines. I finally checked it out with rpm and a newly downloaded copy of vim's
rpm and discovered that exactly one byte, deep into vim, was wrong.

I rebooted my machine (which has been super-solid for years) - and the
difference was gone.

So, what are the opinions - did I run into a hardware glich, or was
there a freaky issue with memory mapping?
If rebooting the machine made the (apparent) error go away,
then my guess would be a bit got flipped in RAM, the page of
RAM that held the cached copy of the page from disk. While
I worked at a large chip company, I heard of cosmic rays,
alpha particles, and such causing occasional soft errors in
RAM. (That's why ECC RAM was a primary factor in the
motherboard I chose when I built my machines.) I would
suggest running memtest86 overnight to check for something
more sinister.

How would an alpha particle (helium nucleus) get through a computer case and
through the plastic of a RAM chip? How could even a beta ray (electrons) get
through a metal case? The only thing I would expect to cause problems would
be gamma rays (cosmic rays). You might as well have ECC RAM (I do).

Yup. any large EMP will corrupt DRAM. Lightning nearby, mains borne interference, strong RF..etc.. however it isn't normally just one byte..
.

Relevant Pages

  • Re: how can a bit be off in memory?
    ... I finally checked it out with rpm and a newly downloaded copy of vim's ... RAM that held the cached copy of the page from disk. ... I worked at a large chip company, I heard of cosmic rays, ... You might as well have ECC RAM. ...
    (comp.os.linux.misc)
  • Re: how can a bit be off in memory?
    ... guess would be a bit got flipped in RAM, the page of RAM that held the ... and through the plastic of a RAM chip? ... cause problems would be gamma rays (cosmic rays). ... The unstable isotope of lead would decay to things that were either stable ...
    (comp.os.linux.misc)
  • Re: how can a bit be off in memory?
    ... RAM that held the cached copy of the page from disk. ... I worked at a large chip company, I heard of cosmic rays, ... The unstable isotope of lead would decay to things that were ...
    (comp.os.linux.misc)
  • Re: Application Fonts on SBS Server rather than workstations
    ... > So possibly just upgrading all the PCs to higher CPUs, faster ram and possibly SCSI 10k rpm HDs would be the better solution for the> workstations due to the way the applications process fonts, etc? ... there should be no less than 2GB of RAM... ... SATA 10K RPM drives should be sufficient, although since you only need high performance for temporary files, you may want some small 15K RPM SCSI drives, as they are quite cheap in smaller capacities. ...
    (microsoft.public.windows.server.sbs)
  • Re: DTV antennas?
    ... I've actually never owned a PC myself that had ECC RAM. ... worth the effort. ... some funny differences between academic level proof and engineering ...
    (sci.electronics.design)