Xbox360 unused protoypes / behind the scenes?

[Pozer]

Just curious if there was more than one design path for the 360 hardware (like sega did with the dreamcast) . I think its been secualted before the RSX was a late addition and early ps3 designs used multiple cells. Also I think the xbox1 was suppose to use an athlon but intel stepped in at the last moment.

Surprising no stories like this with the x360, either their under wraps or the development went smooth.

 

[one]

1. They didn't use strictly off-the-shelf parts this time
2. The development schedule was tight (3 years)