October 1st, 2012, 11:57 AM
is the problem with Transcend Industrial cards limited to sdctl based systems only? Are these issues to be expected on older products with SD card drivers implemented in FPGA? I have TS 7350 on my mind. We are using the Transcend 2G SDs and we have seen some issues with the data consistency but the SD rarely fails completely. From time to time some of the files gets corrupted - the first 25 bytes are overwritten to 0xFFs. Usually overwriting the whole card in a PC is enough to get it working again. Do you think these issues could be somehow related with the failures this thread is about?
December 12th, 2012, 01:05 PM
Since we had to stop using the Transcend industry cards, we have tried a number of different cards and I have to say, that we have encountered similar odd behaviour also with regular non-industry cards from Transcend and Pretec. I can imagine that there is a trend to make the cards "smarter" to get the same lifetime with cheaper chips inside. Hope this will not span across all the brands.
July 29th, 2013, 01:02 PM
A very interesting test. I'd like to hear about other such tests concerned with other devices, HDD for example, of course, if it's possible.
February 10th, 2014, 07:25 PM
This is a very interesting report about ATP cards. We have been having problems with these cards and have developed a test which was able to detect that we were getting random 2K blocks of data from other files being written around the same time. The 2K (0x800) of data was duplicated in 2 locations on the card and the data was always offset by 8K (0x2000) bytes.
We were only able to reproduce this particular failure mode on the latest cards with SN's starting 0x26XXXXXX or later. Earlier cards with SN's starting with 0x1080XXXX or 0x1090XXXX did not exhibit this 2K bug.
February 12th, 2014, 06:09 PM
very useful test. So, given 6TB was the maximum writable data before fault, and 4GB the microSDs, we can say they can be re-writed for at least 1500 times before fault.
June 12th, 2015, 08:47 PM
As the testing data shows, it is difficult to interpret longevity data without knowing exactly which SD card is being tested. Various factors such as SLC versus MLC memory, and wear leveling strategy can result in dramatically affect lifetime.
Sandisk has a new offering to add to their various "MicroSD" flavors, a "High Endurance Video Monitoring MicroSDHC, MicroSDHX" (SDSDQQ-032G and SDSDQQ-064G) marketed for recording HD video loops in dash cams, etc. Ignoring the fine print, the brief specifications from Sandisk suggest the 64G card should have longevity to write 117 TB of data before error, which could be interpreted as a scaled up write-longevity from the tested 4G card (6TB * 64G/4G).
November 10th, 2016, 09:34 AM
I totally agree. A good investment. I've been using my microSD for 3 years extensively, without any issues.
Originally Posted by solelunauno
By joff in forum Embedded Systems Development (Temporary)
Last Post: December 12th, 2012, 01:05 PM
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