Asus KN97 User Manual page 15

III. INSTALLATION
5. CPU External Clock (BUS) Frequency Selection (FS0, FS1, FS2)
These jumpers tell the clock generator what frequency to send to the CPU. These
allow the selection of the CPUs External frequency (or BUS Clock). The BUS Clock
times the BUS Ratio equals the CPUs Internal frequency (the advertised CPU speed).
6. CPU to BUS Frequency Ratio (BF0, BF1, BF2, BF3)
These jumpers set the frequency ratio between the Internal frequency of the CPU
and the External frequency (called the BUS Clock) within the CPU. These must
be set together with the above jumpers CPU External (BUS) Frequency Selection.
WARNING! 68MHz, 75MHz, and 83MHz frequencies exceed the specifications
for the onboard Intel Chipset and are not guaranteed to be stable.
Set the jumpers by the internal speed of your processor as follows:
CPU Model Freq.
[Reserved] 333MHz
Intel Pentium II 300MHz
Intel Pentium II 266MHz
Intel Pentium II 233MHz
Pentium Pro 200MHz
Pentium Pro 180MHz
Pentium Pro 166MHz
Pentium Pro 150MHz
Intel Pentium II Processor in a SEC Cartridge
(233-333MHz 256/512KB L2 Cache)
NOTE: Voltage Regulator Output Selection (VID) is not needed for the Pentium II
and Pentium Pro processors because these CPUs send a VID signal directly to the
onboard power controller.
BF0
BF1
BF2
BF3
2.0x 2.5x
CPU : BUS Frequency Ratio
1 2 3 1 2 3
FS2
FS1
FS0
60MHz 66MHz
CPU External Clock (BUS) Frequency Selection
(BUS Freq.)
Ratio BUS Freq. FS2 FS1 FS0
5.0x 66MHz [1-2] [1-2] [1-2]
4.5x 66MHz [1-2] [1-2] [1-2]
4.0x 66MHz [1-2] [1-2] [1-2]
3.5x 66MHz [1-2] [1-2] [1-2]
3.0x 66MHz [1-2] [1-2] [1-2]
3.0x 60MHz [2-3] [1-2] [1-2]
2.5x 66MHz [1-2] [1-2] [1-2]
2.5x 60MHz [2-3] [1-2] [1-2]
ASUS KN97 User's Manual
3.0x 4.0x 4.5x
3.5x
Reserved for
future CPUs
1 2 3 1 2 3
68MHz 75MHz
(Freq. Ratio)
BF0 BF1 BF2 BF3
[on] [off] [off] [on]
[off] [on] [off] [on]
[on] [on] [off] [on]
[off] [off] [on] [on]
[on] [off] [on] [on]
[on] [off] [on] [on]
[off] [on] [on] [on]
[off] [on] [on] [on]
Intel Pentium Pro Processor
(150-200MHz 256/512/1,024KB L2 Cache)
5.0x
5.5x
1 2 3
83MHz
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