Has anyone noticed a performance improvement when using unsigned short instead of unsigned int for index data? I have tested multiple scenarios(on GeForce 8) and have not observed any improvements. The older GeForce 7 Programming Guide suggests to use unsigned short, at least in the case of SLI (8.6.6).
I imagine three potential reasons that I haven’t seen a performance gain: 1) newer drivers always deal with ints, so the shorts are actually converted to ints, 2) the performance improvement is only noticed in memory constrained situations or when the indices are sent across the PCI-E bus, so using shorts just uses less memory, it doesn’t put you on a fast path, 3) shorts only improve performance on ATI, which I haven’t tested.
I suppose 2 is the most likely reason why I haven’t noticed any performance improvements. Any other thoughts?