Compact flash capacity

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Hi,

Does anyone have sufficient experience with CF devices to know if the
sector count reported by (for example) a 512 MB CF device is such that
all 512MB devices will report the same figure?

I've heard of CF devices containing bad sectors, and was wondering if
the CF's controller did anything clever like 'mapping out' any known
bad sectors (e.g. at fabrication time), which would lead to slight
variations in reported device capacities.

Thanks

David

Re: Compact flash capacity
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No first hand experience, but my personal opinion
is that it would be a serious mistake to assume
that they would.

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I believe that they maintain a hidden reserve
of good sectors to map in.  I also wouldn't be
surprised to discover that they  could run out
of hidden good sectors and start mapping out
"physical" sectors.

There's at least 4 of the internal CF controller
chips on the market and they all appear to be
quite different from one another, so I don't
think you can make any clever assumptions about
how bad sectors are handled.




Re: Compact flash capacity
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No, they dont.  Manufacturers round up and down and use 1000 or 1024
as basis for a KB/MB.  Just like with harddrives, cards vary by a few
percent.

Marc

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