Amiga - a 16bit or 32bit machine?

[Zac67]

Usually the CPU (data bus) defines whether the machine is called 16 or 32 bit (think of a PC 386DX with ISA slots - 32 bit). So all earlier Amigas (1000, 500, 2000, 600, CDTV) are 16 bit machines, later/bigger ones (3000, 4000, 1200, CD32) are 32 bit machines.

When it comes to chipsets, OCS/ECS is definitely 16 bit. AGA is partly 32 bit (graphics data), so I'd call it 16/32 bit.

However, the architecture is based on a 32 bit command set with everything appearing 32 bit wide, 32 bit software etc. So I'd call the Amiga per se a 32 bit system.

[Zac67]

Usually the Data bus and the general purpose registers are the same width...

Not necessarily:
- Z80
- 68008 (!)
- 68000
- 8088
- Pentium (32 bit registers vs. 64 bit bus)
- ...

[Zac67]

IMHO the P4 was pretty much a monstrosity right from the start, built entirely for high clock rates on paper - performance came second.