Asus P I-P55T2P4S User Manual - Page 16

III. INSTALLATION (Jumpers) III. INSTALLATION 5. CPU External (BUS) Frequency Selection (JP11, JP12) 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 (JP9, JP10) 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 (JP11, JP12). JP JP 12 11 1 2 3 JP JP 12 11 1 2 3 JP JP 12 11 1 2 3 JP JP 12 11 1 2 3 50MHz 55MHz 60MHz 66MHz CPU External Clock (BUS) Frequency Selection JP JP 10 9 1 2 3 JP JP 10 9 1 2 3 JP JP 10 9 1 2 3 JP JP 10 9 1 2 3 1.5 x 2.0 x 2.5 x 3.0 x CPU : BUS Frequency Ratio (1.5x, 2.0x, 2.5x, 3.0x) Set the jumpers by the Internal speed of the Intel CPU as follows: Internal Ratio External JP12 JP11 JP10 JP9 166MHz 2.5x 66MHz [2-3] [1-2] [2-3] [2-3] 150MHz 2.5x 60MHz [1-2] [2-3] [2-3] [2-3] 133MHz 2.0x 66MHz [2-3] [1-2] [1-2] [2-3] 120MHz 2.0x 60MHz [1-2] [2-3] [1-2] [2-3] 100MHz 1.5x 66MHz 90MHz 1.5x 60MHz 75MHz 1.5x 50MHz [2-3] [1-2] [1-2] [1-2] [1-2] [2-3] [1-2] [1-2] [2-3] [2-3] [1-2] [1-2] 10 P/I-P55T2P4 User's Manual