Frontside Bus Speed Switch - VIA Technologies A7F129 Manual

1.5. Frontside Bus Speed Switch

Use these switches to set the system's frontside bus (FSB) speed.
Memory Strapping switch (SW1)
2
ON
OFF
Frontside BUS Speed Switch (SW3)
4
OFF
OFF
OFF
Note: A CPU clock speed setting of 100/110 MHz requires that
the installed memory modules are PC-100/133. A setting of 133
MHz requires PC-133 memory modules. The CPU clock speed
setting can be adjusted in BIOS Setup. However, when setting
hardware, you must set the CPU frontside bus speed and clock
frequency as shown below:
CPU frontside bus speed
Frontside Bus Speed Switch
CPU clock Frequency
1 CPU
ON 100 MHz
ON 133 MHz
3 2
ON ON
ON OFF
OFF OFF OFF
(SW3)
100 MHz
110 MHz
133 MHz
A7F129 Quick Reference
PCI
33.33 MHz
33.33 MHz
1 CPU
ON 100 MHz
ON 110 MHz
133 MHz
CPU clock frequency
(SW1)
100 MHz
100 MHz
133 MHz
PCI
33.33 MHz
36.67 MHz
33.33 MHz
5