Intel DZ77GA-70K, Performance Tuning Manual, Page: 13 / 35

Intel DZ77GA-70K / DZ77RE-75K Desktop Board Performance Tuning Guide
13
3.4 Recovering from an Unstable System
Should performance values be set beyond the point of stable system operation, the
system may exhibit a failure to boot, a blue screen, a system hang or a recovery
screen as described in the sections below. Exceeding the system stability limits is a
normal, expected occurrence during the performance tuning process and there are
multiple reliable and easy to use options for restoring system operation as described in
the following subsections.
3.4.1 Hardware Watchdog Timer
A hardware watchdog timer has been included as part of the board circuitry and is
enabled by default in the BIOS. This timer will automatically enable the board to
startup if unstable system operation or a failure to boot is detected. If the watchdog
timer detects an issue, the screen shown in Figure 3.1 will be displayed.
In addition,
on the DZ77GA-70K board at the top of the Diagnostic LED bank, a red LED will
illuminate when the Watchdog Timer is activiated. The user can then go into the BIOS
screen and manually reset performance parameters or use the F9 key to reset all BIOS
defaults to restore system stability. This process can be repeated over and over, so if
the user’s parameter changes do not restore system stability, the watchdog timer will
again intervene and allow the user another opportunity to adjust the BIOS settings.
The watchdog timer works in most, but not all cases. If the watchdog timer did not
detect an issue or was disabled by the user, then one of the alternate recovery options
described in Sections 3.4.2 through 3.4.4 can be used.