You are half right and half wrong. Yes, the Motorola 68000 was a 32-bit CPU INTERNALLY, but all of its bus interfaces and external access registers are 16-bit. Not only that, but the 68k only has '22-bit' capable cache displacement, so it really isn't a 32-bit chip. The 68020 was a full 32-bit chip because it increased the cache layout and reorganized it, and it was full 32-bit bus compliant.Christuserloeser wrote:Seriously, the Super Nintendo had a 3 MHz 16-bit upgrade of an 8-bit CPU but the system successfully competed with the Genesis' powerful Motorola 68k (a 32bit CPU clocked at 8 MHz). Former NES developers had a decent amount of knowledge of the 6502, and the system's design with its focus on the more powerful GPU allowed to make up for the difference
The SNES CPU isn't as weak as you think. Although it is indeed just a 16-bit update (as such is the 68k compared to the 6800), Nintendo stressed powerful integer arithmatic to compensate for lacking feature set. Besides, what the SNES could do at 3.58MHz, the Genesis was struggling to do at 7.61MHz. The 68k was a more all around chip, but relied on clockspeed to compensate for lack of raw arithmatic performance, which the Ricoh 5A22 could do but at half the clock rate.
Also, funny thing, the Xbox CPU is really a Pentium III with half the cache disabled. It still has the same associativity and bus speed, but half of the cache is just like 'lurr lurr lurr' and either isn't working (on early models) or isn't even there (on the later ones).