Is the blank SD card tested?

[diogenes]

Hello, I am sorry if this is the wrong board to ask this question and if this is a silly question but I searched your blog and other forum posts and did not find an answer.

For the product MICRO-SD-CLASS10[1] is each one tested by you? I see that for a similar product A20-SD-CARDS[2] the description says "Tested". I learned about counterfeit SD cards from bunnie's blog[3] and want to learn how to source SD cards reliably. If my aim is to flash each SD card with a custom image, does it make more sense to order the A20-SD-CARDS instead of MICRO-SD-CLASS10 because you already tested them? I think that many people such as myself would be interested in ordering cards for various purposes that you already tested. Many thanks!

[1] https://www.olimex.com/Products/Components/Storage/MICRO-SD-CLASS10/
[2] https://www.olimex.com/Products/OLinuXino/A20/A20-SD-CARDS/
[3] https://www.bunniestudios.com/blog/2010/microsd-card-failures/

[LubOlimex]

We don't test each blank card, but we test few cards of each batch. Also we use the saem blank cards to prepare the A20-SD-CARDS. Also we order from the same manufacturer and haven't had problems so far.

It makes more sense to purchase blank cards and write them yourself, if you are already re-writing it. The A20-SD-CARDS make more sense for beginners and people that don't want to bother with downloading images and writing them to a card themselves. I've written this bit about SD cards in the manual:

"For best experience use a micro SD card with speed rating between class 10 and A1. Using slower than class 10 card might severely degrade the user experience. Beware that A2 or faster cards might lack software support in Linux.
It is recommended to test the SD card beforehand. Most of the problems that appear in a first time boot are related to either the SD card or the powering. There are a lot of counterfeit SD cards out there and also cards tend to get damaged easily. Good software for testing the SD cards is either f3 (fight flash fraud) or H2testW.
"