Whenever I get a new SD card or USB stick, or any kind of storage, I want to test it out to make sure it’s “legit.”
Sometimes, on Amazon and other online stores, they sell knockoff and counterfeit SD cards that don’t really have the advertised capacity or speed.
So before I use them in my drones or cameras, I run them through f3, which fills up the SD card with random data, and verifies the write speed.
you can grab f3 here: GitHub - AltraMayor/f3: F3 - Fight Flash Fraud
Here’s an example (actually an excuse for me to use a new camera!):
After running f3write, it’s a good idea to run f3read of course, which will you if the writing was successful, and if there are any bad sectors on the media.