Asus P/I-P55T2P4S External, Internal, Internal, External, BUS Clock, BUS Clock, CPU External (BUS) Frequency Selection, 6.CPU to BUS Frequency Ratio (BF0, BF1)

INSTALLATION .III (Jumpers)

III.INSTALLATION

5.CPU External (BUS) Frequency Selection (FS1, FS2)

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 ad- vertised CPU speed).

6.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.

1	2	3	1	2	3		1	2	3	1	2	3
FS2		FS2				FS2				FS2
FS1		FS1				FS1				FS1
50MHz			55MHz				60MHz			66MHz
CPU External Clock (BUS) Frequency Selection
BF1 BF0		BF1 BF0			BF0	BF1			BF0	BF1
1			1			1				1
2			2			2				2
3			3			3				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, Cyrix, or AMD CPU as follows:

CPU Model	Freq.				(BUS Frequency)		(Freq. Ratio)
		Ratio	(BUS	Freq.)	FS2	FS1	BF0	BF1
Intel Pentium	200MHz	3.0x	66MHz		[1-2]	[2-3]	[1-2]	[2-3]
Intel Pentium	166MHz	2.5x	66MHz		[1-2]	[2-3]	[2-3]	[2-3]
Intel Pentium	150MHz	2.5x	60MHz		[2-3]	[1-2]	[2-3]	[2-3]
Intel Pentium	133MHz	2.0x	66MHz		[1-2]	[2-3]	[2-3]	[1-2]
Intel Pentium	120MHz	2.0x	60MHz		[2-3]	[1-2]	[2-3]	[1-2]
Intel Pentium	100MHz	1.5x	66MHz		[1-2]	[2-3]	[1-2]	[1-2]
Intel Pentium	90MHz	1.5x	60MHz		[2-3]	[1-2]	[1-2]	[1-2]
Intel Pentium	75MHz	1.5x	50MHz		[2-3]	[2-3]	[1-2]	[1-2]
Cyrix 166+	133MHz	2.0x	66MHz		[1-2]	[2-3]	[2-3]	[1-2]
AMD	100MHz	1.5x	66MHz		[1-2]	[2-3]	[1-2]	[1-2]
AMD	90MHz	1.5x	60MHz		[2-3]	[1-2]	[1-2]	[1-2]
AMD	75MHz	1.5x	50MHz		[2-3]	[2-3]	[1 -2]	[1-2]

10 ASUS P/I-P55T2P4S User’s Manual