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Altera_Forum's avatar
Altera_Forum
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15 years ago

NiosII is slow? Or something I am doing wrong.

Hi all, I am playing with Cyclone II chip. It is custom board and there is ATMEGA16 running at 12MHz and FPGA with master clock 50MHz. FPGA is translating data from internal dualport memory ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Watching the video you posted, it looks to me that the Nios versions are faster than the ATmega version. By the time the ATmega has finished one frame, the Nios II/e has finished almost 3 and the Nios II/e has finished almost 5 frames.

Given the 32 bit vs 8 bit and floating point vs non floating point differences, I too would have guessed there would be a bigger difference. You would have to analyze the compiled code of each in detail to see why it performs the way it does.

You still have not confirmed you actually enabled optimizations in the Nios II version. As others have pointed out -O0 is the default optimization setting which will produce very inefficient code.

Another though I had is that you may want to verify your Nios code is actually using the FP hardware. I don't have any experience with this, but I have seen quite a few other posts on these forums about people having trouble with the compiler not actually using the FP hardware but using software emulation instead.