Cyclone V Clock speed

Let me add to the useful suggestions already given by FvM. You CANNOT rely on simple numbers from a datasheet to find the speed at which your design will run. I know this from hard won experience. You MUST create at least a rudimentary design that is representative of the kind of calculation you wish to perform. Create a simple timing constraint and compile the design. The timing analyzer will then TELL YOU what the maximum operating frequency is. If that frequency is too low then you can investigate pipelining, etc. to speed things up. If your requirement is really 500Mhz it sounds like you probably won't get there under any circumstances.