content: Not enough gates to produce anything comparable to a modern processor. You might be able to create some extremely basic 4 or 8 bit processors with the current FPGA array sizes but a 64 bit processor would not be possible. I think the FPGA performance would drop through the floor once you develop it into a CISC type system since FPGAs are optimized for small and highly dedicated functionality not general purpose functionality. Also, how would you create on-chip cache for your processor out of gates?