Can someone explain the result of the FSB strap change at 401 on these boards?

What happens to what timing signals (RAM frequency) that is different at an FSB of 400 vs 401? If possible could you use my FSB of 400 running my memory at 1:1 (DDR2-800, 400MHz to memory) and tell me what happens to what numbers if I bumped to 401 (I think that's the 'strap change')?

Thanx in advance, Skip