Most tools don’t show reliable progress informationwhen flashing an operating system to an ssd card. In case you use dd to copy, this issue can be solved by the nice pv tool with:

pv -tpreb /path/to/image.img | dd of=/dev/yourUSBorSDSlotTarget bs=1M

which results in:

And really lighten up the time when flashing your Pi devices like Raspberry Pi or BananaPi.