>>3356165
PS1 in theory can do a 256x256 texture per draw call, but loading such large textures frequently puts too much pressure on memory bandwidth. 64x64 RGB textures (4 KB) were pretty much the reasonable limit of what PS1's memory bandwidth could safely accommodate.
N64 can only draw from its 4 KB texture cache, so that is forced size limit per call. However, in practice textures were usually even smaller than that for two reasons.
1) N64's memory bandwidth is high but extremely optimization sensitive due to a very high random access latency. If programmers were able to defragment their memory pools to reduce random accesses then it's really fast, if they didn't do it effectively then it's really slow. The thing is, if you want more performance it's way easier to dumb down your textures than to program a more effective memory manager, so most developers followed the path of least resistance.
2) Mipmaps (if desired, which usually were) reduce texture limit to 2 KB per draw call.
That being said, I am very confident that the N64 with good memory management will beat the PS1 in overall framebuffer texture resolution. Ultimately the N64 has more bandwidth and a larger texture cache than the PS1 so it should in theory churn through those draw calls faster.
Conker's a good example - it doesn't have super high resolution textures, but virtually everything is textured even at a distance, and repetition is low. You couldn't wrestle this kind of quality out of the PS1 - at best you'd need to do heavy tiling or LOD to produce something comparable.