It wasn't really a competition or anything. Besides, both IBM and Motorola made 601s, 603s, 604s, and the PPC 750. IBM made all of the 601s and QFP-style 604s, whereas Motorola seemed to make a disproportionate number of the 603s, in both QFP and BGA packages.
Essentially, IBM said, "Hey, the 603's replacement kicks some ass and has a crazy TDP, so we're not going to bother with a proper successor to the 604." Which is fine, except that the 750 doesn't support SMP without extra hardware or software to make up for the chip's lack of cache coherency, so it wasn't exactly a server or high-end workstation chip. Plus there's the whole 32-bit ALU thing.
Motorola may have been participating in developing the 604's successor with IBM and had simply taken the torch by itself when IBM threw in the towel, or they may have decided that the 750's shortcomings were too much to bear and built it on their own. Whatever the case, the 7400 is essentially a 604 manufactured on a better process (and consequently, with higher clock frequencies), a new bus architecture (MPX), enhanced L1 caches, backside L2 cache support, and, most importantly, the introduction of the VMX subsystem.
Essentially, IBM said, "Hey, the 603's replacement kicks some ass and has a crazy TDP, so we're not going to bother with a proper successor to the 604." Which is fine, except that the 750 doesn't support SMP without extra hardware or software to make up for the chip's lack of cache coherency, so it wasn't exactly a server or high-end workstation chip. Plus there's the whole 32-bit ALU thing.
Motorola may have been participating in developing the 604's successor with IBM and had simply taken the torch by itself when IBM threw in the towel, or they may have decided that the 750's shortcomings were too much to bear and built it on their own. Whatever the case, the 7400 is essentially a 604 manufactured on a better process (and consequently, with higher clock frequencies), a new bus architecture (MPX), enhanced L1 caches, backside L2 cache support, and, most importantly, the introduction of the VMX subsystem.