Do Memory Cards Wear Out?

[Fleetwood271]

It matters whether the SSD drive uses SLC or MLC memory. SLC generally endures up to 100,000 write cycles or writes per cell, while MLC can endure anywhere from 1,000 to 10,000 writes before it begins to fail.

This does not mean that the card be can formatted 100,000 times. It means that each cell can be written and erased (or over written) from 1,000 to 10,000 times for MLC memory and upto 100,000 times for SLC memory.

Each cell stores 512 bytes
1,000,000 bytes - 1 Megabyte
1,000,000 divided by 512 = 1953.125
1,954 cells are used for every 1 MB of use.

Let's say you take a picture as a high res jpg and it is 8 megs. That will use 13,672 cells. Now let's say you take 100 pictures, that's 195,313 cells used.

It is these cells that can written to 1,000 to 10,000 times (MLC) or upto 100,000 times (SLC).

Wear leveling will be the same cells from being written to unless the other cells have been written to already, so that you do not get a hotspot. Otherwise if each image, of each day, used the first 13,672 cells, those cells would use up their write-cycles quickly.

Hopefully that clears up basically how the SD card wearing works.

Thanks!

 

[Fleetwood271]

Yes! But! It's not likely to happen in your lifetime: Flash memory - Wikipedia, the free encyclopedia

Memory wear

Another limitation is that flash memory has a finite number of program-erase cycles (typically written as P/E cycles). Most commercially available flash products are guaranteed to withstand around 100,000 P/E cycles, before the wear begins to deteriorate the integrity of the storage.[SUP][8][/SUP] Micron Technology and Sun Microsystems announced an SLC flash memory chip rated for 1,000,000 P/E cycles on December 17, 2008.[SUP][9][/SUP]

Thanks Keith!

 

[NikonME]

Thanks!

No problem. Glad to be of assistance.