When I target a Radix-4 implementation, the resource count in the GUI is more than what I see in the MAP report. Why?
There is a problem with the resource estimation, when targeting a Radix-4 implemenation, where the resource estimation can be off by a factor of 2. (i.e. , The GUI might say 104 DSPs, but the final implemenation is only 54.)
To find the correct resource usage, see the MAP report.
For a detailed list of LogiCORE Fast Fourier Transform (FFT) Release Notes and Known Issues, see (Xilinx Answer 29209).