Cpu Core Speed Derivation Procedure - MSI -5149 User Manual

2.1-2 CPU Core Speed Derivation Procedure

1. The 4 CPU clock frequencies that the system supports are 50 MHz,
55MHz, 60MHz and 66.6MHz (To adjust SW1 pin 1, 2 , and 3). See the
following chart to set the different Host Clock Frequencies.
ON
OFF
ON
OFF
2. The DIP Switch SW1 (4, 5 and 6) is used to set the Core/Bus (Fraction)
ratio of the CPU. The actual core speed of the CPU is the Host Clock
Frequency multiplied by the Core/Bus ratio. For example:
If CPU Clock
Core/Bus ratio
then CPU core speed
OFF
ON
ON
OFF
OFF
OFF
Note:
3. The PCI Bus Clock is the CPU Clock Frequency divided by 2.
1 2
ON
ON
OFF
OFF
4 5
OFF
OFF
ON
ON
ON
OFF
Shaded Part are used by Intel
TM
with MMX
3 CLOCK
OFF 50MHz
OFF 55MHz
OFF 60MHz
OFF 66.6MHz
= 66.6MHz
= 3/2
= Host Clock x Core/Bus ratio
= 66.6MHz x 3/2
= 100MHz
6 Core/Bus Ratio
OFF 1.5
OFF 2
OFF 2.5
OFF 3
OFF 3
OFF 3.5
®
technology and AMD
2-2
Pentium ® processor
®
K6