On Wednesday 06 June 2012, Arnd Bergmann wrote: (this was David's bad card) > > > > MMBTR16GUBCA-ME > > | CYJ485GA 144 > > Made in TAIWAN > > > > but I might have an error there (it is tiny). > > Hmm, it had not occurred to me to compare the numbers on the card, rather > than those > on the packaging ;-) > > Now my excellent "Essential" (blue label) 32 GB class 10 card looks like this > > MMBTR32GUBCA-AB > S 32GBUSD1 132 > Made in Korea > > while my bad "Essential" 8GB looks the same from the front with the blue > label, but > has more text on it: > > MB-MS8GA > MBMS8GVCDBCA-RF > ICY11447QZ142 > MADE IN TAIWAN > DESIGNED BY > SAMSUNG
fwiw, the ones above were produced in 12/2011 and 02/2012, respectively. I've got a few more samples now: * Excellent Transcend-branded 32GB class 10 microsdhc made by samsung, produced 01/2012 (identical to my Samsung above): MMBTR32GUBCA-AB S N3TVDD9I 203 Made in KOREA * Bad 8 GB microSDHC class 6, produced 09/2011, blue label, "essential series", identical behavior to bad essential 8GB above CE MMBTR08GUBCA-ME I CYG498GA 135 Made in TAIWAN * Bad 8 GB SDHC (not micro, class 6, red label, produced 12/2011, idential behavior to previous one. MB-SS8GA MBSS8GVCDBCA-RF D OLX00000 1 4 7 MADE IN KOREA DESIGNED BY SAMSUNG This unfortunately proves that not all "made in korea" cards from samsung are good, which would have been too easy. It's had to find a pattern here, and I could still use more samples. What we have found out by now is that: * Made in Korea doesn't mean it's good, but all good cards we've seen so far are made in Korea. * The string MB-SS?GA does not mean it's good or bad * The string MMBTR??GUBCA seems to have the same meaning and also doesn't mean it's good or bad. * All good cards that we have seen have this string followed by -AB * All bad cards that we have seen have this string followed by -RF or -ME * The three-digit number at the end is always different and has some relation to the production date, but it's not monotonically increasing across different lines. * All fast cards so far are 32GB, all slow ones are between 4 and 16GB I also found a little bit of information at http://www.scribd.com/doc/90864328/Samsung-FLASH-Product-Guide That information suggests that the -AB line is only used for the 32 GB TLC flash based cards, and that it uses a "VJX" controller, as opposed to the "SS66512" controller used in the smaller TLC based cards with the -ME postfix. The "VJX" name sounds similar to what the same document calls their eMMC controllers, and the behavior of that device is also what I'd expect from an eMMC. Arnd _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
