The media is likely to be defective.
482.0 MByte OK (987184 sectors)
7.1 GByte DATA LOST (14933968 sectors)
Details:7.1 GByte overwritten (14933968 sectors)
0 KByte slightly changed (< 8 bit/sector, 0 sectors)
0 KByte corrupted (0 sectors)
2 MByte aliased memory (4096 sectors)
First error at offset: 0x000000001e006000
Expected: 0x000000001e006000
Found: 0x00000001e5c06000
H2testw version 1.3
Writing speed: 1.92 MByte/s
Reading speed: 9.11 MByte/s
H2testw v1.4