The energy-saving mode of system.
Options:
1.basic(1) -when it is set to basic(1), the system energy saving mode is basic mode.
2.deep(2) -when it is set to deep(2), the system energy saving mode is deep mode.
3.optimal(3) -when it is set to optimal(3), the system energy saving mode is optimal mode.
4.standard(4) -when it is set to standard(4), the system energy saving mode is standard mode.
The default value is basic(1).