18 ASUS TX97-X User’s Manual
III. INSTALLATION
(Jumpers)
III. INSTALLATION
6. CPU External (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 CPU’s External frequency (or BUS Clock). The BUS Clock
times the BUS Ratio equals the CPU's Internal frequency (the advertised CPU speed).
7. CPU to BUS Frequency Ratio (BF0, BF1)
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 : BUS Frequency Ratio
CPU External Clock (BUS) Frequency Selection
50MHz
FS1
1
2
3
FS0
FS2
55MHz
FS1
FS0
FS2
1
2
3
60MHz
FS1
FS0
FS2
1
2
3
66MHz
FS1
FS0
FS2
1
2
3
BF1
BF0
1
2
3
BF1
BF0
1
2
3
BF1
BF0
1
2
3
BF1
1
2
3
BF0
R
2.5 x3.0 x2.0 x3.5 x
2.5 x3.0 x2.0 x1.5 x
2.0 x3.0 x2.0 x3.0 x
Intel P54C
Intel P55C
Cyrix M1
Set the jumpers by the Internal speed of the Intel, AMD, or Cyrix CPU as follows:
(BUS Freq.) (Freq. Ratio)
CPU Model Freq. Ratio BUS Freq. FS2 FS1 FS0 BF1 BF0
Intel Pentium 200MHz 3.0x 66MHz [2-3] [2-3] [1-2] [2-3] [1-2]
Intel Pentium 166MHz 2.5x 66MHz [2-3] [2-3] [1-2] [2-3] [2-3]
Intel Pentium 150MHz 2.5x 60MHz [2-3] [2-3] [2-3] [2-3] [2-3]
Intel Pentium 133MHz 2.0x 66MHz [2-3] [2-3] [1-2] [1-2] [2-3]
Intel Pentium 120MHz 2.0x 60MHz [2-3] [2-3] [2-3] [1-2] [2-3]
Intel Pentium 100MHz 1.5x 66MHz [2-3] [2-3] [1-2] [1-2] [1-2]
Intel Pentium 90MHz 1.5x 60MHz [2-3] [2-3] [2-3] [1-2] [1-2]
Intel Pentium 75MHz 1.5x 50MHz [2-3] [1-2] [2-3] [1-2] [1-2]
AMD-K5-PR133 100MHz 1.5x 66MHz [2-3] [2-3] [1-2] [1-2] [1-2]
AMD-K5-PR120 90MHz 1.5x 60MHz [2-3] [2-3] [2-3] [1-2] [1-2]
AMD-K5-PR100 100MHz 1.5x 66MHz [2-3] [2-3] [1-2] [1-2] [1-2]
AMD-K5-PR90 90MHz 1.5x 60MHz [2-3] [2-3] [2-3] [1-2] [1-2]
AMD-K5-PR75 75MHz 1.5x 50MHz [2-3] [1-2] [2-3] [1-2] [1-2]
*Cyrix 166+ 133MHz 2.0x 66MHz [2-3] [2-3] [1-2] [1-2] [2-3]
*NOTE: Only Cyrix Revision 2.7 or later is supported on this motherboard. See next page for revision
identification. Bootup screen will show 6x86-P166+ with the Cyrix 166+ installed on this
motherboard.
