Why do I experience slow Fmax for Nios II system in Arria V (non GZ family)?

When user selects "DSP Block" implementation as the Hardware multiplication type for Nios® II, users may observe slower Fmax performance in Nios II system. This is because Arria® V (non GZ) family does not supports 32-bit multiplication in its hard multiplier logic which results in additional LEs being instantiated. The hard multiplier together with the additional LEs will create critical path in Nios II.

Users can switch to "Logic Elements" implementation or "None" as the Hardware multiplication type for Nios II if the application code does not need multiply instruction.