the board has no impact on multitasking whatsoever
also usually a 6500 is by far enough
furthermore the only reason to get a Z170 board is for overclocking (apart from some very specific things like 3way-Crossfire or sth like that)
while the H110 is pretty basic a H170 can unleash the full potential of a 6500/6700
generally the H110 board will do fine as well and wouldn't give you any problems (apart from the 2 RAM slots and the restricted PCI lanes on the board)