Cool.
Generally, processor daughtercards designed for the same motherboards are interchangeable no matter the speed or CPU count. That was true as far back as the PCI-class Macs where you could swap dual processor cards for singles and vice versa. A few G4s in the Sawtooth era couldn't take a dual processor card in place of the stock single CPU because Apple firmware got in the way somehow. That's the only case I'm aware of where that general statement above doesn't hold true.
Peace,
Drew
_________________
Power to the PowerPC!
Generally, processor daughtercards designed for the same motherboards are interchangeable no matter the speed or CPU count. That was true as far back as the PCI-class Macs where you could swap dual processor cards for singles and vice versa. A few G4s in the Sawtooth era couldn't take a dual processor card in place of the stock single CPU because Apple firmware got in the way somehow. That's the only case I'm aware of where that general statement above doesn't hold true.
Peace,
Drew
_________________
Power to the PowerPC!