The opteron cores are not as efficient per ghz as the haswells. The only advantage is that you have physical cores without any hyperthreading. I'll try and compile the miner on 12.04 to run it on bare metal and see what/if any advantages are seen vs running it kvm with cpu passthrough.
The server is about $3300, so it's not exactly cost effective. Just fun to see.
edit: just noticed the instructions to install it on 12.04, derp.
methinks its the Opteron machine.
Wolf0, thanks for sharing. I should not be surprised that the coder of the miner is very effective at managing his rented rigs, and I am not really, but I gotta say that your ~64 h/s/core is quite impressive on the c3.8xlarge instances.
Actually, I can get 70H/s/core on c3.8xlarge, 64H/s/core is just with this miner...