OK, so went for a fly this morning and after a couple of minutes I got this message:
That card looks fake, where did you purchase it from?
The printing on the card is very inferior!
It’s just old, prob got from Amazon and have been using them both for a while without issue. The image is from a heavily cropped image off my iPhone
Are you on MacOS? If so this speed-check app is brilliant to check.
@OzoneVibe Thanks Dave. On with it now.
Even if that card is legit, I would recommend these. I only use them in my drones and never have an IO or write speed errors.
32GB like for like, under a tenner, you can’t go wrong …
@clinkadink I’ll give them a try, thank you. Below are the results from the test suggested by @OzoneVibe …All seems to be OK so i’m still confused.
Maybe try a re-format and test it again in the drone 
@OzoneVibe Advice taken and they’re winging their way to me from Amazon as we speak.
Had this on Mavic 3 with this old class 10 card did firmare update & started getting errors until i replaced with cheap U3 card from amazon & the problem never happened again also had the same issue with Avata. I loathe to throw anything away 
@OfficerDoofie Hmmm yeah, me too. I will find something for them however.
What is that test measuring?
There’s no way your card is writing at over 2000MB/s
V30 is guaranteed to be over 30MB/s
That’s more like PCIe speeds of you main storage.
@callum I think you are correct. I just hit the start button after installing it and that’s what came out. I have now read up on the operation of the app and can now confidently say that the attached image is the real one. Hopefully this makes more sense.I have taken the test a couple more times and they are about the same. (i don’t know what they mean but can confirm their similarities, which, i hasten to add are different / lower than the other card of the same breed.
Thanks for looking.
Speeds look fine.
On windows I normally use H2testw.
It’s a more complete stress test and checks storage capacities and overall integrity of the card.
You can see from this example the card is writing but it’s full of errors that would t be picked up on a simple speed test.
I’m not sure if there’s a Mac equivalent.
Probably easiest to just bin the card if others are working.
@callum
Yeah, new ones coming tomorrow.
There is a replacement called F3 but it’s far too complicated for me as it means going into Terminal and for me that’s a no no.
Cheers buddy
That was an exciting half an hour 
H2test is much better for catching cards with faked capacity as it writes the full disk size to check it doesn’t start overwriting data. It’s what you’d see on counterfeit cards that say 64gb but are only like 4 in reality.
I have had some success with this (https://www.sdcard.org/downloads/formatter/) and failing cards (short arms, long pockets). it may be worth a try. (benchmark before & after)
still a risk that you lose something later though 
I’ve said this before, but I believe Amazon is the new Fleabay. They will let anyone sell anything on there. It’s worth checking things out.
