the jury is out anyways on weather it will be better to buy next gen cards vs these fpga deals too many moving oarts imo, need new motherboards specific cpus etc , how bout i grab a gtx 1180 for $600 that hashes at stright up twice the hash rate of an 1080 and worry about fpga later when new 8 card boards with better features come out.
It makes no sense to replace hardware (mother boards and cpus) with new gear unless you are building a new system or app specific boards are released.
fuck risers