Notes about the dd command in Linux.

dd if=inputfilename.iso of=/dev/sdX

This command was slow, no progress was displayed and I had no idea if the command was working succesfully or not. Not possible to kill the process once started so I needed to shutdown to stop the process.

dd if= of=/dev/sdX bs=4k status=progress oflag=sync

This was from the Funtoo Install Guide. It worked reliably with progress indicator but again very slow, taking a couple of hours to complete.

dd if=/path/to/image.iso of=/dev/sdX bs=8M status=progress oflag=direct

From the Fedora Docs this command worked reliably with progress indicator and quickly too.

Found a comment from StackExchange about combining small block size with oflag=sync reducing performance and that not using oflag=direct can lead to issues too. I think next time I might try with oflag=direct,sync and an 8M block size, lowering that if the result is unsucessful.