At 04:26 PM 6/11/1998 Thomas Bubacz wrote:
>
>I just bougth a DFI model P5BTX/l Rev B motherboard which has a "switching
>voltage regulator that supports 2.8v to 3.5v core voltage.  I will be
>installing a pentium 200mmx cpu.  The manual is clear on how to set the
>"external Bus Clock-frequency Ratio" on what they call SW1.  It is SW2 which
>sets the "core voltage" that confuses me.  The options are 2.8(board
default),
>2.9, 3.2, 3.3, 3.5.  From what I gather from Intel's site, part of the
>processor uses 2.8 and other parts use 3.3.  What do I use, am I reading too
>much into this ?


Thomas:

The Intel MMX (P55C) uses dual [power plane]
voltages of 2.8v internal (Core) and 3.3v external.

The reduced voltage results from a more
efficient and reduced size circuitry and allegedly
reduces heat. The external voltage of 3.3 matches
the I/O's voltage.

So, you set the Core Voltage for 2.8v and the
external (I/O) voltage for 3.3 (you may not even
have a jumper setting for this).

Regards,

John Chin