My brother showed me that yesterday. It is cool indeed, but only to have an idea of the current state of the technology.
They updated the video and the description to include the total price of $30k, when i watched it he only said it costed "as much as a decent brand new car". The CPUs alone probably cost more than $5k each, and those 32GB ECC DDR4 sticks probably cost as much as the R9 Nano, if not more.
The most interesting fact in the project was the power efficiency, both in idle and under load. A single rig with an i7 and a R9 Nano will pull more than 300W under load, and 7 of those will pull more than 2kW
Fun stuff
