Performance Impact while enabling Data Volume Encryption

Data volume encryption only incurs an overhead when data is decrypted during read from disk and encrypted when writing to disk. Data in memory is always decrypted and therefore there is no performance penalty associated with access to in-memory data.

Scenarios that involve access to data volumes and therefore have a performance impact are:

Area:

Column loads    
Savepoints and database snapshots
Data backups
Hybrid LOBs

These scenarios are dominated by I/O and the encryption related CPU overhead is minor. Usually the overall performance impact isn't higher than a medium single-digit percentage.