Q:

Mining Performance of AMD Radeon Pro Duo

I would like to evaluate the purchase of that GPU for Ethereum Mining. Does someone already have benchmarks?

A:

We just received ours ... 42m/h atm @ 370w ... mainly due to the 16.5.3 driver ... 

A:

No benchmark looks to be available and i think it's due to the fact that this card looks to be very expensive and quantity is limited. However, the pro duo seems to be a radeon fury x2. So you can imagine that, as fury x looks to be around 30MH/s, this card would be 60MH/s. However for the same hashrate you can use 3 radeon r9 290 with some oc and it will cost you less than $600 instead of $1800 for the pro duo.
Hashrate is more a matter of memory interface speed than a mater of GPU power. AMD indicated a 4096 bits memory interface. This is huge. So you may have a very good hashrate. But is it valuable in front of multiple small cards? I don't know. Still power consumption will be lower with only 300W. So until you try, we won't know.

