f3write

The f3write command line tool is a part of the F3 (Fight Flash Fraud) suite of tools used for testing and verifying the authenticity of storage devices, especially flash drives or SD cards. It is specifically designed to test the actual capacity of a storage device and check for counterfeit or fake drives that claim to have more storage space than they actually possess.

When executed, the f3write tool writes a series of test files to the storage device, filling it up to its maximum claimed capacity. These files are generated using a pseudo-random number generator to achieve a realistic data pattern. By filling the device to capacity, f3write can test if the device performs as expected and if there are any issues with memory mapping, flash translation layers, or invisible/hidden memory on the storage device.

The f3write tool uses the FAT32 file system format for compatibility with a wide range of devices. It can be used on various operating systems like Linux, macOS, and Windows.

When combined with the f3read tool, which reads back the previously written test files, the f3write tool helps to detect if a storage device is counterfeit or if it suffers from data corruption or hardware issues.

Overall, the f3write command line tool is a valuable tool for testing and validating the integrity and capacity of flash drives and SD cards, ensuring that users are not deceived by counterfeit storage devices.