the only problem with zombie mode is that you need a gen 3 PCIE and cannot use risers...
It will be nice if it works on gen 2 pci-e
It does work on PCI-E Gen 2. But you can't rely on risers and low lanes slots, true. A x16 PCI-E Gen 2 slot would perform equally well as a x8 PCI-E Gen 3 slot.
Son benchmarks on a 580 4G on epoch 500, that is more than 1 is still 7 mh/s ...
That means the Zombie Mode will be for a long while... At the moment is the most profitable solution connected in MOBO for a 4Gb Cards with 24-25Mhs
I wondered about the viability of Zombie mode as well. I ran a few tests on a Radeon 7970 (3GB) at epoch 254 it would do 25mh/s. Unfortunately zombie mode seems not be to implemented for 3GB cards, at least in my case once i raise the epoch further the hashrate would be 0mh/s. I'd reckon by your results it would still offer something in the range of 5-10mh/s. Of course it may be smarter to mine altcoins with a lower epoch.