SD card speed

M. Warner Losh imp at bsdimp.com
Mon Aug 14 18:46:57 UTC 2006


In message: <44E053CE.4090304 at fernuni-hagen.de>
            Marc van Woerkom <marc.vanwoerkom at FernUni-Hagen.de> writes:
: What the heck is the difference between
: a formatting done with sysinstall's fdisk
: and Windows XP's format?

Chances are that there's a 'mbr signature recognition' that looks for
certain kinds of FAT file systems so that the part can implement an
improved 'wear averaging' algorithm that knows which sectors are
unused giving it a much larger pool to rotate wear through, especially
in low allocation situations.  How to make FreeBSD's fdisk do the
right thing is an interesting question...

There are some CF parts that are 4x slower at write when you format
them for ffs than when you format them for FAT.

Warner


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