I have One Controller flashed with the 750 firmware. I did this to up the share rate by using 1 card from my version 1 Z9 mini. It did up my share rate as it seams, one hash board is enough to do the work and my coin rate went up using 1 Z9 as 2 Z9s. Both overclocked at 750 with a 5500rpm fan the highest temp is 70C. But, as I learned more about using the miner in this way it ups the share rate with a combined hash rate of 16.5 KH/s. But your chance or luck to find a new block goes down. I just purchased a second version 1 Mini and I will be able to make 3 miners running 12 kh/s for a total hash rate of 36K on the pool and an even higher share rate; but again Luck goes down in this config in finding blocks. I will try it to see how it works and I will report back.