For open source hardware I doubt you'll see people shell out the cost of a used car to be able to match modern ~$200 GPUs.
I don't even what to know what Stratix 10 starts at.
The Xeon Phi board https://www.cnet.com/products/intel-xeon-phi-coprocessor-712... is $4.2K..$5K
The Stratix V board will not consume more than 60W when used as PCI Express card. The requirements for Xeon Phi is at least 250W.
With a difference of ~200W, there will be difference in ~4.5kW/h per day or ~1600kW/h or $160 in hard cash per year (US average). Very probably more - getting rid of heat produced, etc.
This was admittedly a space certified radiation hardened chip. Still alarming when you had to pick it up and carry it somewhere