NiosII is slow? Or something I am doing wrong.

I think the II/f looks significantly faster. The II/e core is _not_ designed for any sort of performance application. It's silly to even attempt it if you know what's happening...one instruction every 6 clock cycles.

Besides, you don't use a softcore for performance reasons. You use it "because it (or the FPGA) is there" or because you want to take advantage of FPGA hardware (RTL) acceleration for your algorithms/protocols/whatever.

Cheers,

--slacker