User Guide

Hardware Installation
2-8
2.2.2 Selecting the CPU Frequency
S1
OFF
ON
ON
OFF
ON
ON
OFF
OFF
S2
OFF
OFF
ON
ON
OFF
ON
ON
OFF
S3
OFF
OFF
OFF
OFF
ON
ON
ON
ON
CPU Frequency Ratio
1.5x (3.5x)
2x (6x, 3.33x)
2.5x (1.75x)
3x
4x
4.5x
5x (2.33x)
5.5x (2.66x)
Intel Pentium, Cyrix 6x86 and
AMD K5/K6 CPU are
designed to have different
Internal (Core) and External
(Bus) frequency. The ratio of
Core/Bus frequency is
selected by the switch 1-3 of
SW1.
Note: Intel PP/MT MMX 233MHz is using 1.5x jumper setting
for 3.5x frequency ratio, and AMD PR166 is using 2.5x setting
for 1.75x frequency ratio.
Core frequency = Ratio * External bus clock
ON
1 2 3 4 5 6 7 8
1.5x (3.5x)
ON
1 2 3 4 5 6 7 8
2x (6x, 3.33x)
ON
1 2 3 4 5 6 7 8
2.5x (1.75x)
ON
1 2 3 4 5 6 7 8
3x
ON
1 2 3 4 5 6 7 8
4x
ON
1 2 3 4 5 6 7 8
4.5x
ON
1 2 3 4 5 6 7 8
5x (2.33x)
ON
1 2 3 4 5 6 7 8
5.5x (2.66x)