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SD cards life cycle
#1
I never had issues with CF cards on my cameras for more than ten years, nor with SD cards in 750D for more than one year. However on phones that's a totally different story.

I noticed three SD cards died this year on my Windows phone which sounded strange for me. All three were high quality lexar and sandisk 64 GB cards, they became corrupted: The data was there, you can read it, but you can't write anything new, you can't format it.

My own interpretation is cards have a limited read/ write number of cycles which is hard to reach on cameras easy to reach on mobile phones especially when apps are stored on the card, mainly apps that do a lot of disk writing like web browsers, the same thing happened on my father's Windows phone.

On my wife's phone, the apps are stored on the phone memory only downloads, photos and videos are on the cards it has been there for two years and counting.


So my recommendations for longer cards life would be, limit the read/write use, don't let software create temporary/ swap files on them, personally I don't review/delete photos on camera, I leave everything then after downloading photos I delete faulty ones.
#2
Recommendation: Ditch the Windoes phone and get an iPhone with enough memory (they do not do SD cards with flash memory, so the issue is void).

#3
Longevity is normally determined by number of writes; though heat can also play a role. I've been using the same micro-sd in my andriod phone(s) for the past 7 years (I use it for the camera).

-

anyway I wonder if the ms phone is slamming useless writes to the sd card. Not sure if there are tools to monitor writes on the phone and I don't think sd cards have smart data. hum.... anyway windows is a dead platform for phones; get an android phone (iphone sucks).

#4
I could imagine, you're on the wrong track.

 

Android phones (with their linux cores) would mount a card read-only if

they could not repair the filesystem after an inconsitency (and thereby they

would show the behaviour you observed) ... wether or not you could format them

in this state, is a question of the software used ... physically it should be

possible.

If a windows-phone behaves the same is out of scope of my experience.

 

But I can assure you, the number of write-cycles (reads do not harm) might be

limited ... normal use in a phone will not wear a card out that much that you

could notice it. All cards use wear-leveling and also have a certain amount

of extra cells that are being used when other cells die ... with that, you should

not experience errors due to "excessive" amounts of writes when used in a smartphone.

 

Rainer

#5
I haven't had any issues with any of my SD-cards so far. I only use Sandisk cards, though, and after I learned the lesson the hard way, I buy exclusively from very trustworthy sources.

I have one "Sandisk" Ultra that showed issues after several months of use. Checking the card carefully it turned out that the write and read speeds of that card were way below specs. It's very likely that this card is fake and just relabeled as Sandisk.

So, you should maybe check where you bought the cards and if they are original Sandisk.
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#6
A flash storage device is divided into blocks (the size of a block depends on the device, usually between 64 and 256KB). The number of times a block can be erased is limited : from 10'000 times to hundreds of thousands of times, depending on the device. Usually, you get what you pay for. Cheap quality deals don't really exist.

 

Reading and writing doesn't affect the life of a block, it's only the erasing that wears out, not the writing. The reason people think that writes are limited is because one needs first to erase a block before writing to it.

Because blocks can only be erased a certain number of times, manufacturers reserve spare blocks that are not visible to the user. When a blocks is failing (can't be erased properly), the firmware of the device maps a new block from the spare ones. This is why performance degrades over time and when there are no more spare blocks available, users starts to see corrupted blocks (leading to corrupted files).

 

High grade flash memories are much higher rated in terms of erase capacity. The worse flash memories are found in SD cards. USB sticks tend to be better and SSD drives are at the top of the food chain in terms of reliability (i.e. number of erase cycles). In fact, a good SSD drive today is more reliable in the long run than a classic magnetic hard disk.

 

Please not that what I say above applies to any flash device (including built-in flash found in phones or anywhere else).

 

If you want to maximize reliability, check the specs of a flash device in terms of write cycles and buy accordingly, or use a camera featuring dual SD card slots and configure the camera to write the same file on both cards.

--Florent

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#7
Windows uses disks to swap memory, it can well be that current Windows phone also does that (it would not surprise me, microsoft seems to not think things through a lot), wearing flash memory out quickly?

#8
So my suspicions are correct, the phone is using the card for cache data this leads to its gradual wearing
#9
How very odd. I had zero issues with SD cards, including swapping them in and out of an Android phone. Apart from microSD->SD adapters that cease to work (three of 'em!) and losing the cards altogether (now that DOES suck).

My latest endeavour was to pilfer a 64GB SDXC card from the office and to format it to FAT32 so that I could use it in my camera that does not support SDXC. It worked. Smile
#10
I think you are missing the point.  toni-a is using a windows phone and the suspicion is that the windows phone has greatly increase the write/erase cycle on the card not seen with other (andriod) phones.

 

Quote:How very odd. I had zero issues with SD cards, including swapping them in and out of an Android phone. Apart from microSD->SD adapters that cease to work (three of 'em!) and losing the cards altogether (now that DOES suck).

My latest endeavour was to pilfer a 64GB SDXC card from the office and to format it to FAT32 so that I could use it in my camera that does not support SDXC. It worked. Smile
  


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