Asus P/I-XP55T2P4, User Manual

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10 ASUS P/I-XP55T2P4 User’s Manual
III. INSTALLATION
(Jumpers)
III. INST
ALLA
TION
7. CPU External Clock (BUS) Frequency Selection (JP9, JP10)
These jumpers tells the clock generator what frequency to send to the CPU to 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).
8. CPU to BUS Frequency Ratio (JP12, JP13)
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.
1
2
3
JP9
50MHz
55MHz
1
2
3
60MHz
1
2
3
66MHz
1
2
3
CPU External Clock (BUS) Frequency Selection
CPU : BUS Frequency Ratio (1.5x, 2.0x, 2.5x, 3.0x)
JP10
1.5 x 2.0 x 2.5 x 3.0 x
JP9 JP10 JP9 JP10 JP9 JP10
1
2
3 1
2
3 1
2
3 1
2
3
JP12 JP13 JP12 JP13 JP12 JP13 JP12 JP13
Set the jumpers by the Internal speed of the
Intel, AMD, or Cyrix
CPU’s as follows:
(BUS Freq.) (Freq. Ratio)
CPU Model Freq. Ratio (BUS Freq.) JP10 JP9 JP13 JP12
Intel Pentium 200MHz 3.0x 66MHz [2-3] [1-2] [2-3] [1-2]
Intel Pentium 166MHz 2.5x 66MHz [2-3] [1-2] [2-3] [2-3]
Intel Pentium 150MHz 2.5x 60MHz [1-2] [2-3] [2-3] [2-3]
Intel Pentium 133MHz 2.0x 66MHz [2-3] [1-2] [1-2] [2-3]
Intel Pentium 120MHz 2.0x 60MHz [1-2] [2-3] [1-2] [2-3]
Intel Pentium 100MHz 1.5x 66MHz [2-3] [1-2] [1-2] [1-2]
Intel Pentium 90MHz 1.5x 60MHz [1-2] [2-3] [1-2] [1-2]
Intel Pentium 75MHz 1.5x 50MHz [2-3] [2-3] [1-2] [1-2]
AMD 100MHz 1.5x 66MHz [2-3] [1-2] [1-2] [1-2]
AMD 90MHz 1.5x 60MHz [1-2] [2-3] [1-2] [1-2]
AMD 75MHz 1.5x 50MHz [2-3] [2-3] [1-2] [1-2]
*Cyrix 166+ 133MHz 2.0x 66MHz [2-3] [1-2] [1-2] [2-3]
*The only Cyrix CPU that is supported on this motherboard is labeled Cyrix 6x86
P166+ but must be Revision 2.7 and later. Look on the underside of the CPU for the
serial number. The number should read G8DC6620A or larger.