SD-cards provided with KESS and KTAG don’t meet the standards to be able to have a serial number (CID) identical between them. Indeed, for the KESS or KTAG to work, the contents of the SD-cards must be encrypted in relation to its CID.
Speed is not the most important.
But a SD card with a writing speed of 0.063MB/s is a very bad SD card.
The most important is to have a reliable SD card for a good and reliable rework.
Sandisk Ultra SD-card & Samsung evo plus card:
I have buy samsung evo plus card (10/2017) and cid is not changeable. I have used Sandisk Ultra SD-card solution and all works fine. Tested on edc16u31 edc16u34 and edc17c46 on bench and all work ok. Btw new samsung evo plus card (unchangeable cid) 95mb/s 32gb work great (speed) tested on raspberry-pi image compared with sandisk 32gb sd card and it work also good in ktag.
class 4 card:
kess and ktag fw support only max. speed for class 4 card
class 10 working as class 4 in the hardware
china card with one CID working slow as class 1,2
That is, class 4 should be enough.
The most important is to have a reliable and good quality SD card. (Not like China SD card)
sasmung sd card (original):
In any case, the sasmung sd card (original) is better than the cards that come in Chinese clones and no name sd-cards. Of course, the maximum speed is limited to the hardware and software features of the NXP microprocessor.
kingston 4gb sd card:
ktag 7.020 works fine with kingston 4gb. It’s from obd2diy.fr
Samsung evo card:
Gold card is just for Android smartphone.
Only some Samsung evo from 2015 have a security security breach that allows to change the CID.
Sandisk Ultra SD-card:
I tested Sandisk Ultra SD-card and it works great!! Since i prepared my kingston sd card i have no more « exception eefface » problem. Tested with my ktag 7.020!
THE MOST IMPORTANT NOTE:
…edits cards in manual.
It is very difficult and very slow, there is a « human factor », high probability to be mistaken.
…mistake can kill ECU.
Best decision to use cards with custom CID or cards « Samsung EVO », which allow to change CID.