This is the signature feature. The tool performs a “Full Capacity Test” by writing data to every available block on the drive. If the drive reports it is 64GB but fails the test at 16GB, you know it’s a fake.
Identifying if a drive’s reported capacity matches its physical NAND flash memory. Mydisktest V2.42
Today, while reputable brands have made the market safer, the "fake capacity" scam still persists on massive third-party marketplaces. The DNA of MyDiskTest lives on in modern tools like H2testw and FakeFlashTest. This is the signature feature