You're welcome.
Honestly given the way the high-volume market's moving I expect reliable
small-sized SD cards to be sold only through nice specialized channels - which
means they won't be available at a low price!
Another key advantage with modern SATA SSDs is that wear-levelling and error
correction are *way* better than SD - designed of course for the average person
to run a regular desktop OS on a regular PC-class machine i.e. *lots* more
write-cycles than say on a typical digital camera or smartphone. This is an
important point to consider if one would like to have a decent product MTBF but
leverage high-volume market price points in the product BOM cost.
If form factor is an issue then you can take a look at the Slim SATA (not to be
confused with the slimSATA connector!), CFast or UM-SSD form factors - there is
a wide choice of vendors out there, including ones that specializing in
industrial/military grade products.
While I understand the "waste of space" concern, which seems more prevalent in
people coming from the classic embedded system world there are (at least) two
advantages to be gained with having more storage ->
1- you can run a full-featured userland with modern tools and scripts to manage
the OS. It really irks me sometimes when I have to sacrifice core OS management
features to run a busybox userland in a few MB.
2- customers are always asking for higher resolution measurements, better
availability and faster time to turn data into useful information. Also data
duplication is a good technique to improve system reliability.
--- In Simon Leung <> wrote:
>
> Thanks for the information. It looks like I'm in an awkward situation:
> old but potentially more reliable <2G card are getting harder and harder
> to come by. SATA hard drives cost much more than a SD card and it's just
> a waste of space.
>
> hmmmm.
>
> On 07/04/11 12:05, Matthew Smith wrote:
> >
> > FWIW - we've also seen file system issues when using SD cards. particularly
> > when running at high temperatures.
> >
> > I also can confirm that SDHC cards (>2GB) do not work correctly using the
> > TS SD kernel driver. Curiously a 4GB or 8GB SD card partitioned using the
> > 512MB partition table provided by TS (e.g.
> > ftp://ftp.embeddedarm.com/ts-arm-sbc/ts-7800-linux/binaries/ts-images/2.6.34-512mb-sd.dd.gz)
> > works OK. As soon as the partition table is modified to include partitions
> > that are greater than 2GB or are set at a>2GB boundary then errors are
> > observed when reading or writing files.
> >
> > It is also impossible to edit the partition table using fdisk on the TS7800
> > (tested on both Debian Lenny and Squeeze). Using the MMC drivers on an
> > OpenRD (my main build machine for kernel compilation and OS image creation)
> > I do not see this issue.
> >
> > As an alternative I am currently testing SATA-based storage using Intel
> > X25M Postville SSDs - so far this is looking really good, huge performance
> > increase and RAID1 mirroring too!
> >
> > For new applications I'm becoming quite insistent on using SATA instead of
> > SD/MMC/USB storage.
> >
> > cheers
> > Matt
> >
> > --- In "al"<mitch.stanek@> wrote:
> >> We have also seen premature SD card failure. Although anecdotal, our
> >> observations seem to indicate lack of quality in recently manufactured SD
> >> cards from some Taiwan-based firms. Cards from other manufacturers seem
> >> to last longer. Older SD cards with lower capacities have been in use for
> >> years in our experience, so the manufacturing process for smaller
> >> geometries must be more challenging than they can admit to.
> >>
> >> So, I would say the system is reliable, but the SD cards are not. ;-)
> >> Good luck (to us all) in finding reliable SD cards...
> >>
> >> --- In Simon Leung<simonleung@> wrote:
> >>> Thanks for the reply.
> >>> ...
> >>>
> >>> I've replaced the SD card with another one and the problem seems to be
> >>> gone (for now). If this is indeed a SD card issue, then the system is
> >>> not very reliable in this regard: it's only been in use for a few weeks.
> >>> And it's meant to be for month.
> >
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
>
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