The P100s have full support for half-precision (i.e. 16 bit) floating point ops. This can mean ~2x improvements in speed and memory usage in comparison to the Pascal TitanX, which is the top "consumer" card. This difference is significant for almost any machine learning workload, which is what a lot of these cards will be used for.

NVIDIA gimped half-precision on the consumer cards to drive datacenters, hedge funds, machine learning companies, etc. towards the "professional" cards (and their huge markup).