as of current i can buy a 1.25 single CPU upgrade for my MDD for 13 bucks. I can also buy a 167MHz Logic board for 30. I can get a Dual 1.25 for $170 just by itself. Being that my MDD now has a 1GHz, will i notice a speed difference by increasing it 25MHz? It was suggested before that i could get Dual 867MHz and see a slight speed increase and use my current logic board. IIRC the non-FW800 MDD did have the option for a 1.25 single upgrade. If I am not mistaken on that, how would i know if this 13 dollar CPU is 133 or 167MHz? EDIT: CORRECTION: It is listed as a 167 bus. It is also listed as sealed in box Manufacture refurbished.