Asus P/I-P55TP4N - Manual (Page 16)

P/I-P55TP4N User's Manual 10
III. INSTALLATION
(Jumpers)
III. INST
ALLA
TION
5. CPU External (BUS) Frequency Selection (JP26, 27, 28)
These jumpers tells the clock generator what frequency to send to the
CPU. These allow the selection of the CPU’s External frequency (or
BUS Clock). The BUS Clock times the BUS Ratio equals the CPU's
Internal frequency (the advertised CPU speed).
6. CPU to BUS Frequency Ratio (JP14, 15)
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.
CPU External Clock (BUS) Frequency Selection
CPU : BUS Frequency Ratio (1.5x, 2.0x, 2.5x, 3.0x)
1.5 x 2.0 x 2.5 x 3.0 x
60MHz 50MHz
JP26
1
2
3
JP27 JP28 JP26
1
2
3
JP27 JP28
66MHz
JP26
1
2
3
JP27 JP28
JP14
JP15
JP14
JP15
JP14
JP15
JP14
JP15
Set the jumpers by the Internal speed of the Intel CPU as follows:
Internal (CPU) Ratio External JP28 JP27 JP26 JP14 JP15
166MHz 2.5x 66MHz [2-3] [1-2] [2-3] [short] [short]
150MHz 2.5x 60MHz [1-2] [2-3] [2-3] [short] [short]
133MHz 2.0x 66MHz [2-3] [1-2] [2-3] [open] [short]
120MHz 2.0x 60MHz [1-2] [2-3] [2-3] [open] [short]
100MHz 1.5x 66MHz [2-3] [1-2] [2-3] [open] [open]
90MHz 1.5x 60MHz [1-2] [2-3] [2-3] [open] [open]
75MHz 1.5x 50MHz [2-3] [2-3] [1-2] [open] [open]