The max hashing rate is the max clock * 5.66 (see page 1) = 5.66*954 = 5.4Mh/s that's the absolute max one should be able to squeeze of it. If all cores are alive that is. You tune the core voltage to whereever the HW error rate is under 2-3% (see page 1 again). Mem voltage is a little more flexible now because of the auto-restart. It will get a lot hotter so you should still monitor, even with the fan. If you have only 1 unit that's easy but if you have many close together it is important.  I would think start with a quarter turn on the core voltage and see how that goes. Don't go much higher to 0.9V setting.