From my understandings each acorn will boost 4 gpu's 30Mh/s so two would gain you an additional 30Mh/s for a total of 60. This is for ETH and that's about it all I know if certain GPU's will gain more or less I guess we have to wait to find out. Who knows what other algo gains will be if any. But it at least looks like it will make the whole system more efficient.
I thought it was 30MH/s total regardless. 30MH/s per card up to four cards would be incredible.
I also believe that it is 30MHs total. Also, there will be no such increase for ethash (especially with GTX1080ti running with a "pill"). The savings are mostly for power, in such case. Can we please get an official clarification on this. I am mostly interested in ethash