Prerequisites For Using The AMD K6-2+
Only revisions 3.x and later of the Asus P55T2P4 support the new AMD K6-2+.
An important prerequisite for running the AMD K6-2+ on the Asus board is the correct core voltage of the processor. Whether the P55T2P4 supports the necessary core voltage of 2.0 volts or not depends mainly on the actual board revision. Generally the motherboard must be equipped with two switching voltage controllers (split-plane design), one for the CPU core voltage and one for the I/O voltage. This feature was originally intended for the upcoming Pentium-MMX processors back then. Officially the board only offers core voltages between 2.5 and 2.9 volts. However, the controller is capable of supplying voltages between 2.0 and 3.5 in small increments. Our table lists the missing undocumented voltage values. In order to adjust to 2.0 volts all four pins between 2.5 and 2.9 volts must be closed with a jumper.
Undocumented feature: The old Asus board supports a core voltage of 2.0 volts. You have to close all four pins between 2.5 and 2.9 volts with a jumper.
Voltage Settings Of The Asus P55T2P4 (Rev. 3.x)
Voltage Settings Of The P55T2P4-S
These tables contain all undocumented settings for the core voltage. The bottom table shows the jumper configuration for the P55T2P4-S.