Intel 815TM5 User Manual page 43

HARDWARE SETUP
Intel 815 Micro-ATX Mainboard
(B) JP2: CPU Voltage (Vcore) Range Selection (optional)
The voltage regulator on the mainboard will generate 1.3V ~ 3.5V DC to support
different processors. Basically, most mainboards will use the CPU VID signal
(VID0~VID4) from the CPU to decide the proper CPU core voltage (Vcore). In
case that there is the poor connection between CPU and its socket, or uninstall the
CPU from the mainboard while the system power is "ON". Under such
circumstance, mainboard may receive wrong VID signal and send wrong Vcore to
the CPU. Unfortunately, wrong Vcore may destroy the CPU and the mainboard.
In order to protect the mainboard and the CPU from the unexpected damage, JP2
is introduced on the mainboard to control the Vcore within the safe range so that it
won't make any damage to the CPU or mainboard because of wrong VID signal.
Since most Pentium II/!!! processors require the Vcore below 2.05V except few
Pentium II processors. So the default setting of JP2 will control the Vcore between
1.3V and 2.05V so that the CPU and mainboard will have a good protection.
Please do not change the setting on JP2 unless your CPU needs the voltage higher
than 2.05V.
JP2
OPEN: Vcore = 1.3V ~2.05V
SHORT: Vcore = 1.30V ~3.50V
Socket
370
+
CPU Vcore Range Selection
Note: When JP2 is not installed on the mainboard, then the
Vcore range will be 1.3V ~ 2.05V.
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