Erase methods and SSDs
An erase method defines how O&O SafeErase overwrites data: which pattern it writes and how many passes it makes. The default method is suitable for current drives; methods with more passes take considerably longer without making the erasure more secure.
You set the default method under Settings > Deletion method. Before each erasure, the erase job shows the method under How, and you can choose another one for this run.
Methods
| Method | Passes | Pattern |
|---|---|---|
| NIST 800-88 Clear / BSI CON.6 (1× random data) (default) | 1 | Random data. Corresponds to "Clear" in NIST SP 800-88 Rev. 2 and to the complete overwrite with random data required by the BSI IT-Grundschutz module CON.6. |
| Overwrite with zeros | 1 | Zeros. Fast, but only a basic erasure. |
| US DoD 5220.22-M (Legacy) | 3 | Random data, zeros, random data. |
| Previous BSI procedure (Legacy) | 6 | 00, FF, 00, FF, 00, random data. |
| US DoD 5220.22-M ECE (Legacy) | 7 | A fixed sequence of patterns and random data. |
| Gutmann Method (Legacy) | 35 | The patterns that Peter Gutmann described in 1996 for magnetic hard disks of that time. |
Methods marked (Legacy) remain available for existing settings and requirements. According to NIST SP 800-88 Rev. 2, several passes are unnecessary on current drives.
The report names the method that was actually used for each target. A method name describes the procedure; it is not a certification of the erasure. Check the result in the report.
The estimated duration in the erase job depends on the amount of data, the speed of the drive, the method and other activity on the PC.
SSDs and SolidErase
On an SSD, the controller decides where data is physically written. It distributes writes across the flash cells and keeps spare areas that Windows cannot address. Overwriting several times therefore brings no additional security, but wears out the SSD.
With Delete SSDs with SolidErase turned on under Settings > SSDs (the default), O&O SafeErase erases detected SSDs with SolidErase instead of the selected method. SolidErase overwrites the data once with random data and avoids unnecessary write cycles. The report notes that SolidErase was used instead of the selected method.
Software can only overwrite the areas that Windows can address. Areas that the controller has reserved or remapped are not reached. SolidErase is not a firmware command such as Secure Erase or Sanitize, nor a cryptographic erase.