3 ms·

Some of them have legit self-sigs. Also cosmic rays?

msbarnett 10y ago
IBM estimated in the '90s that an average desktop computer experienced soft-errors from cosmic rays (energetic neutrons striking a memory cell or data bus, perturbing it enough to flip a bit) at a rate of 1 incident/per 256 Megs of RAM/per month
- sosuke 10y ago
  I want to know more that sounds awesome: Was this it? http://domino.research.ibm.com/tchjr/journalindex.nsf/0b9bc46ed06cbac1852565e6006fe1a0/922f6bbd8495db1485256bfa0067fc4e!OpenDocument http://domino.research.ibm.com/tchjr/journalindex.nsf/0b9bc4... http://www.ida.liu.se/labs/eslab/SNDFT/docs/IBMdram.pdf http://www.ida.liu.se/labs/eslab/SNDFT/docs/IBMdram.pdf "This clearly indicates that because of cosmic rays, for every 256 Mbytes of memory, you'll get one soft error a month," said Tim Dell, senior design engineer for IBM Microelectronics. "The same phenomenon for hard errors with multiple bits will also come into effect with soft errors."
- semi-extrinsic 10y ago
  Cosmic rays are a big problem for supercomputers. There was a very interesting piece [1] on it in Spectrum recently. One of the funniest anecdotes was about a DEC AlphaServers machine installed at Los Alamos, where they had to put a running server blade inside a neutron beam and confirm the error rates spiked in order to convince the manufacturer that the machines were improperly shielded. [1] http://spectrum.ieee.org/computing/hardware/how-to-kill-a-supercomputer-dirty-power-cosmic-rays-and-bad-solder http://spectrum.ieee.org/computing/hardware/how-to-kill-a-su...
cyphar 10y ago
Cosmic rays can cause bit-flips (as sibling commenter mentioned). But there's also other interesting ways that bits can flip in memory. For example, Sun had an interesting issue with their SRAM where their manufacturer had accidentally doped the SRAM with radioactive boron. This resulted in alpha particles being emitted that caused corruption in the SRAM (which then caused Solaris to crash because they had parity bit checking).
makomk 10y ago
Other than the TI calculator firmware signing keys and alice@example.com, do any of them have valid self-signatures?

IBM estimated in the '90s that an average desktop computer experienced soft-errors from cosmic rays (energetic neutrons striking a memory cell or data bus, perturbing it enough to flip a bit) at a rate of 1 incident/per 256 Megs of RAM/per month

sosuke 10y ago
I want to know more that sounds awesome: Was this it? http://domino.research.ibm.com/tchjr/journalindex.nsf/0b9bc46ed06cbac1852565e6006fe1a0/922f6bbd8495db1485256bfa0067fc4e!OpenDocument http://domino.research.ibm.com/tchjr/journalindex.nsf/0b9bc4... http://www.ida.liu.se/labs/eslab/SNDFT/docs/IBMdram.pdf http://www.ida.liu.se/labs/eslab/SNDFT/docs/IBMdram.pdf "This clearly indicates that because of cosmic rays, for every 256 Mbytes of memory, you'll get one soft error a month," said Tim Dell, senior design engineer for IBM Microelectronics. "The same phenomenon for hard errors with multiple bits will also come into effect with soft errors."
semi-extrinsic 10y ago
Cosmic rays are a big problem for supercomputers. There was a very interesting piece [1] on it in Spectrum recently. One of the funniest anecdotes was about a DEC AlphaServers machine installed at Los Alamos, where they had to put a running server blade inside a neutron beam and confirm the error rates spiked in order to convince the manufacturer that the machines were improperly shielded. [1] http://spectrum.ieee.org/computing/hardware/how-to-kill-a-supercomputer-dirty-power-cosmic-rays-and-bad-solder http://spectrum.ieee.org/computing/hardware/how-to-kill-a-su...

cyphar 10y ago

Cosmic rays can cause bit-flips (as sibling commenter mentioned). But there's also other interesting ways that bits can flip in memory. For example, Sun had an interesting issue with their SRAM where their manufacturer had accidentally doped the SRAM with radioactive boron. This resulted in alpha particles being emitted that caused corruption in the SRAM (which then caused Solaris to crash because they had parity bit checking).

makomk 10y ago

Other than the TI calculator firmware signing keys and alice@example.com, do any of them have valid self-signatures?