AM likely has far more than 4 PH/s hashing right now. They've been building their farm since mid July. That 5 Ph/s is just a small slice set aside for the specific purpose of selling mining contracts.
Do you think AM self mining is bigger or smaller than KnC farm?
Remember the good old days where you could just go to blockchain.info/pools and see the AM's share of the network? And from that, infer the actual hashing power? I wish ASICMINER had a bit more transparency, at least about what is actually going on, how much hashing power is deployed, etc.