> > >
> > > Given that it happens so rarely, that parity is only 50% likely to
> > > catch the error anyway, and that parity requires an extra 12.5% DRAM,
> > > it doesn't seem worth it to me. ECC is more useful, since it will
> > > correct single-bit errors rather than just hanging.
> > >
> > > -Matt
>
> No, surely the parity is virtually 100% certain to catch the error...??
> The only way it wouldn't is for more than the one bit to be in error
> in such a way that the parity becomes valid again. If bit errors are
> so rare, it's an unlikely situation, so the parity bits should be a
> good test. However, it's so rare, and parity bits themselves can be
> subject to error, I wouldn't bother with it. They don't either!
The probability that a reported parity error is due to a error in the
parity bit is 1/9. Parity errors are rather rare; thus that type of
error is even more unlikely.
>
> Karl
>