The core runs at 2.8, the I/O runs at 3.3.... this is refered to as split rail voltage, and occurs in all CPU's with MMX except the Winchip by IDT. I am not familiar with your board, but on my own, the I/O jumpers and the Core Jumpers are different colors... your manual should clarify... the voltage settings are very important. I wish I could be more helpful, but I really don't know what your mobo looks like. Frank B Smith >"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 ? >