I don't know why they spread these settings all over about 5 screens, since they all work in tandem together. I find that summarizing them in one place helps me design my optimal configuration. Here's is my current configuration:
.........................................................On Battery.. Plugged In
Power & Sleep
...Screen............................................5 minutes... 10 minutes
...Sleep............................................. 5 minutes... 10 minutes
Additional Power Settings
...When I press the power button...... Hibernate..... Sleep
...When I press the sleep button........ Hibernate..... Sleep
...When I press the close the lid......... Hibernate..... Sleep
Advanced Power Settings
...Sleep = > Hibernate after:............... 5 minutes..... Never
This configuration is designed to preserve battery power, particularly in light of the SP4's battery drain issue while sleeping.
There may be other settings that come into play here, but these seem to me to be the primary ones for preserving battery power.
