Dell PowerEdge C6100 Hardware Owner's Manual page 52

Option
Load Optimal
Defaults
Load Failsafe
Defaults
52
Using the System Setup Program
Description
Select this item and press Enter, a dialog box asks if you want to
install optimal settings for all the items in the Setup utility. Select
[OK] to indicate Yes, and then press Enter to install the optimal
settings.
The optimal settings default values are quite demanding and your
system might not function properly if you are using slower memory
chips or other kinds of low-performance components.
If you select this item and press Enter, a dialog box asks if you want
to install fail-safe settings for all the items in the Setup utility. Select
[OK] to indicate Yes, and then press Enter to install the fail-safe
settings.
The fail-safe settings default values are not demanding so a system
should be able to operate with the fails safe settings even if it is
installed with slower memory chips or other kinds of low-
performance components.