P6LX2-A User’s Manual
3:
Reconfiguring Your Mainboard – 3.8
Installing A CPU Upgrade
If you are installing this mainboard it will not have a CPU
installed unless your vendor installed one when you purchased
the board. If the mainboard is installed in a system, there will
already be a CPU installed. In either case the information and
procedure for installing a CPU is the same. Since the more likely
scenario is that you are installing an upgrade, this section assumes
that is what you are doing. If you need to install the CPU Reten-
tion Module, please see Section 2.
The Basic Procedure
To install a Pentium II upgrade you need to set up the main-
board for the correct CPU speed by doing the following:
•
Set the Internal Clock Factor
You configure the Internal Clock Factor by adjusting jumper
settings on the board. In order to do this, you will need to know
internal clock speed of the Pentium II you want to install.
The internal clock speed is the speed the CPU operates at to
process data and is the one used by CPU manufacturers to indi-
cate the speed of the chip, for example, a 266MHz PentiumII
®
.
The CPU also has an external bus clock speed which is the speed
at which it interacts with external components. The external bus
clock for this mainboard is 66MHz
Configuring Internal Clock Speed & Factor
To configure the board for a CPU’s internal clock speed, you
have to set the clock factor so that the result of multiplying by
the 66MHz external bus clock is the internal clock speed of the
CPU you are installing. For example, the default setting for this
mainboard is:
66.6MHZ [external clock] x 4.0 [clock factor] =266.4MHz
or, an effective setting of 266MHz.
Since the internal clock speed the CPU is supposed to operate
at is fixed, the two factors, external clock and clock factor, are the
variables.