3 ms·
Not necessary, see the original paper. For example, SECDED (single error-correction, double error- detection) can correct only a single-bit error within a 64-b
by lelf 12y ago
Not necessary, see the original paper.
For example, SECDED (single error-correction, double error- detection) can correct only a single-bit error within a 64-bit word. If a word contains two victims, however, SECDED cannot correct the resulting double-bit error. And for three or more victims, SECDED cannot even detect the multi-bit er- ror, leading to silent data corruption.
Edit: link http://users.ece.cmu.edu/~yoonguk/papers/kim-isca14.pdf http://users.ece.cmu.edu/~yoonguk/papers/kim-isca14.pdf
- acveilleux 12y agoTechnically, SECDED cannot reliably detect errors involving more then 3 bits since they might generate a valid code, they might not however and in that case they might be detected as single or double bit error or possible something else.
- yuhong 12y agoAlso the typical reaction to an uncorrectable ECC error is to halt the system with a NMI.
- makomk 12y agoYeah, ECC is going to make exploiting this reliably a lot harder - you'd need to flip three or more bits in the right combination, without first hitting a combination of bits that'd be detected as an uncorrectable error. Google's report suggests they haven't even been able to cause uncorrectable two-bit errors yet, let alone undetectable three-bit ones.