the author doesn't make the data representation explicit, but if doubles are used for positions, 4000 triangles alone would be 288,000 bytes (8 bytes * 3 indice

the author doesn't make the data representation explicit, but if doubles are used for positions, 4000 triangles alone would be 288,000 bytes (8 bytes * 3 indices * 3 vecs * 4000). 4,000 of each would spill the largest L1 cache I know of on a mainstream processor (512 KB) and they would still be too big to fit in L1 cache of most modern CPUs even if the vectors used floats. it wouldn't be a huge margin though. I agree with your point 2) in general. first try for the closest mapping between language semantics and program semantics. come back and do weird stuff later after profiling.