ASROCK A75M-DGS Installation Manual page 10

Erase Count. The default is 1.
Erase Pattern The default is 55AA (hexadecimal)
5 Press Ctrl-E to continue. The confirmation screen displays.
6 Press Ctrl-P to secure erase your physical drive. Watch the screen to monitor the progress.
Secure Erase runs until all sectors of the selected physical drive have been overwritten. Depending on the size of your
physical drive, this operation can take some time. You cannot exit the Option ROM Utility until the Secure Erase is
done.
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