Yes, the "neural accelerators" in the M5 GPU cores really do 4x pre-fill performance over M4. You can find benchmarks online since M5 has been out for months now. I assume the M6 has whatever the next-gen version of those is. These are not the "neural processors" that have been there since M1 (those still exist) but are additionl matrix math accelerators inside the actual GPU cores. Like "tensor cores" on Nvidia GPUs.