Agp Ratio - AOpen AX6BC User Manual

Hardware Installation

2.2.4 AGP Ratio

JP23 AGP Ratio
1-2 Auto (default)
3-4 2/3
5-6 1/1
There is a "66/100" signal pin from CPU for BX chipset to automatically identify
AGP clock, this is important for jumperless design. When a 66MHz Pentium II
CPU is used, the north bridge will synchronize the CPU external frequency and
the AGP bus frequency. Therefore, when you set the CPU external frequency to
100MHz, the AGP bus will also runs at 100MHz.
With 100MHz Pentium II CPU, the north bridge automatically set AGP frequency
to 2/3 AGP frequency. In other words, the AGP card will still runs at 66MHz while
the CPU is running at 100MHz external frequency.
Except Auto setting, you may also set this jumper to 2/3 or 1/1. Below is a table
for better understanding:
CPU Type 66/100 signal
66MHz Low
66MHz Low
66MHz Low
100MHz High
100MHz High
100MHz High
100MHz High
100MHz High
100MHz High
Warning: The specification of AGP is maximum 66Mhz
clock. If the bus clock is larger than 66MHz, setting this
item to Enabled may cause serious system damage.
2-6
To improve system
implemented this jumper for AGP to synchronize the
CPU 100Mhz (or above) external frequency. We
recommend you choose a better AGP card for
overclocking. Some AGP cards can not take 100MHz
bus frequency and may cause overclocking failure.
JP23
1
3
5
Auto
(Default)
Bus clock
66MHz
100MHz
100MHz
100MHz
100MHz
100MHz
133MHz
133MHz
133MHz
performance, AX6BC
JP23
1
2 2
3
4 4
5
6 6
2/3
AGP clock JP23
66MHz 1-2
100MHz 1-2
66MHz 3-4
66MHz 1-2
66MHz 3-4
100MHz 5-6
88.6MHz 1-2
88.6MHz 3-4
133MHz 5-6
has
JP23
1
2
3
4
5
6
1/1