how to measure microsd wear

[Rodney W. Grimes]

> 
> > On Jan 21, 2017, at 3:40 PM, Karl Denninger <karl at denninger.net> wrote:
> > [ SD cards can fail ]
> 
> I have to second the assertion that even the comparatively pricy SanDisk Ultra SD cards can fail in production scenarios all the time, nor do they even need to be used in a more advanced filesystem role.  I go through a lot of those cards just using them to shoot a lot of GoPro footage (video and still photos) and  I usually get a few weeks out of each card, filling it almost entirely with footage several times a day, before it write locks and is ready for the bin.  This is why I also shoot a lot of redundant footage with multiple GoPros, and anyone using these cards extensively for digital photograph or video will tell you the same.
> 

I think I can add some light as to the higher failure rate in your digital video photography usage of the SD cards, your actually likely to write every single block of the device at a pretty regular rate, where as a file system is going to have hot spots of data that gets updated often, but at no where near the over all block write rate your doing in digital photography.

I suspect using one as a drive in a security DVR would make for a good write cycle life counter.  Probably wearing them out at the rate Jordan is seeing in the GoPro's.

In either case the manufactures of flash devices have made it very clear that these things DO have a write cycle life time, and that your going to see a failure eventually if you write enough data to them.


-- 
Rod Grimes                                                 rgrimes at freebsd.org