G4 Chip Constraints (Score 1)

Apple isn't even shipping the G4s yet. In fact, even though they say they will ship soon, something tells me it's going to be very hard to find a G4 for the next few months. This is especially true of the "advanced" Sawtooth-G4s, as the 400Mhz version is really just a Yosemite-G3 motherboard with a few tweaks (the G4 is pin-compatible with the G3, and no additional hardware is required for its operation- that "extra hardware for 4 streams of data" is just a recompile for AltiVec). Anyway, my guess is Apple disabled the G4 in the BWG3s so that they would be the only effective buyer of G4s until it was being produced in enough quantity to not matter. As an upgrade company, if the G4 won't work in the G3, why would I buy any G4s? It's a defensive maneuvre on Apple's part to make sure that they have enough of a supply of the chip to make the real deal.