P100 has HBM2, not HBM1. We ordinary folk don't know how well it performs or overclocks, though I'd assume it has extremely high performance due to the memory bandwidth it affords.
P100 = full fat Pascal. Anything else is cut down.
We know how HBM2 performs, its on the Tesla cards and the clockspeed is very poor.
The funniest thing is both the GP100 Tesla card and the GP102 Pascal Titan are using the same amount of active cores yet the TDP on the lower clocked Tesla card is 50 Watts higher than the Titan. The major difference is the Tesla card has HBM2, you know the memory that is supposed to use a lot less power, could this been the reason it is not on the higher clocking Titan lol.