[Tfug] Media cards

[Tom Rini]

On Sun, Jan 04, 2009 at 09:43:49AM -0800, Bexley Hall wrote:

> Hi,
> 
> "Standards are great; everybody should have (at least!) one"
> 
> <frown>
> 
> There seem to be more d*mn media card standards than there
> are media card manufacturers!
> 
> SD, SDHC, CF, MS, SM, each of the preceding with "high speed"
> option, etc.  (yes, there are several others, as well  :<  )
> 
> I'm trying to figure out which to use in a new design.
> I think all except CF are intended as "secondary storage"
> as they all have serial interfaces.  I.e., you can't do XIP
> using them (well, not unless you keep faulting in pages!)
> 
> But, CF is big, bulky, more prone to damage, etc.
> 
> Any thoughts on this?

All of the removable ones are designed for, well, being swapped in and
out.  If you want primary the question is, will the data be modified a
lot or not?  The big big flash chips (the name of which escape me) have
a smaller number of writes before you start seeing bad blocks.  But the
filesystems for them are designed with this in mind.  For not-so-big,
regular old NAND is probably your best bet.

-- 
Tom Rini