Yes, you are right in this statement, but I do not want to write a long story. It seems that Ethash is only algorithm that is not suitable for FPGA.
Not so fast, there is a guy who claimed he can do Ethash at 421.41 MH (FPGA Nallatech 385A). I am still waiting for proof, so it may be possible. Or I may be waiting for a very long time.
https://github.com/Maetti79/OpenCL_FPGAhttps://github.com/Maetti79/ethminerIve tried to contact Maetti79 about that number. The only response I received was theyre making huge progress and he would give more info soon. That was about a month or so ago. It seems people get too caught up in making money to help others. I commend whitefire990 for what he's working to accomplish