DFI 586STE User Manual page 18

After setting these jumpers, the CPU will multiply the external bus clock by
the frequency ratio to become the internal clock speed. Internal clock speed
is the commonly used speed of the processors in the market and is the
actual operating clock of the processor.
external bus clock x frequency ratio = internal clock speed
Jumper JP6 is used to set the cache burst mode of your processor. Refer to
the following pages and set this jumper accordingly.
Jumpers JP3, JP5 and JP14 are used to set the voltage of your processor.
Make sure these jumpers are set correctly, otherwise your system will hang.
The table below shows the External Bus Clock of the CPUs supported by
the system board and their corresponding PCI Clock and Bus Clock.
External Bus Clock
50MHz
55MHz
60MHz
66MHz
18
PCI CLK
ISA Bus CLK
25MHz
8.333MHz
27.5MHz
9.1666MHz
30MHz
7.5MHz
33MHz 8.25MHz