5.1.5. Compilation Messages
If the reports show resource usage lower than 100%, but the design does not fit, either resources are insufficient or the design contains invalid assignments. In either case, the Compiler generates a message in the Processing tab of the Messages window describing the problem. As resource utilization approaches 100%, the design becomes increasingly difficult to fit.
If the Fitter finishes unsuccessfully and runs much faster than on similar designs, a resource might be over-utilized, there might be an illegal location or timing assignment that is difficult or impossible to resolve.
If the Intel® Quartus® Prime software takes too long to run when compared to similar designs, the Compiler may not be able to find a valid placement or route solution. In the Compilation Report, look for errors and warnings that indicate these types of problems.