Date   : Sun, 24 Jul 2011 09:42:21 +0100
From   : philb@... (Phil Blundell)
Subject: 16 bit IDE interfaces with microdrives

On Sat, 2011-07-23 at 15:21 +0100, Michael Firth wrote:
> Is there a reason to prefer a Microdrive over the same capacity of CF card,
available new at a similar price?
> 
> http://prodigytek.co.uk/product_info.php?products_id=399&c=node&i=B000VY7HYM

I don't expect speed will be an issue either way, though I suspect data
retention will probably be better with the microdrive.

Most of the consumer-grade CF and SD cards you can buy today are
probably using MLC flash which requires fairly careful supervision if
you want your data to stay intact.  In particular, each block of MLC can
only be read from a certain number of times before it needs to be erased
and rewritten.  There's also the wear-levelling issue which is more
severe with MLC because the write cycle endurance of each block is less
than SLC by about a factor of 10.  

That's not to say that it's necessarily impossible to make a reliable
card out of MLC, but it requires a fairly sophisticated controller and
my experience has been that a lot of the lower-end cards either don't
have the right level of technology for that, or haven't been
appropriately tested and don't actually work correctly.  On some of the
cards we tested recently at work, just reading from the same file a
couple of thousand times would cause the data to gradually become
corrupt.

Plus of course a spinning microdrive just seems cooler somehow :-)

p.