As it relates to Ravencoin mining with FPGAs, OP will need to store over 300 million bitstreams to account for every possible combination. Better get back to the drawing board because this design will never work.
For Ravencoin and Bitcore, the DDR4 is not used for hashing at all, but rather to store hundreds of different FPGA configuration bitstreams, which allows the entire FPGA to rapidly reprogram itself on every block based on the algorithm sequence for that block.
Partial reconfiguration - you dont need every combination, just every building block.