[DNF2]

I don't really believe you ran either the Mojo or the Julia code. There's no way your single-threaded C code outperformed multi-threaded simd optimized Julia or Mojo. It's flat out impossible.

The only other explanation is if you ran the non-simd Julia version under a single thread.

[bjourne]

I ran this Julia code which one of the thread participants claimed to be the "best": https://discourse.julialang.org/t/julia-mojo-mandelbrot-benc... Run your own benchmarks if you don't believe me. IDGAF.

[sundarurfriend]

Just to make sure, did you start Julia with multithreading enabled? `julia --threads=auto` should do it (or `julia -tauto` if you prefer).

Without it, Julia starts single threaded, which means the code does all this work to enable multithreading and then doesn't get to benefit from it.

[bjourne]

I did. Running with threads improves performance by 50%, but is still nowhere near C performance. My machine only has two cores so threading doesn't help much.

[sundarurfriend]

That's interesting. It makes sense that a two core machine doesn't benefit too much from multithreading, but "nowhere near C performance" is pretty surprising. I'll try out both the programs around this weekend on my own fairly anaemic machine, and see how they fair for me. Thanks for responding!

[bjourne]

Cool. If Julia runs much faster for you than for me I'd be interested in hearing it. I was honestly surprised the performance was so bad so perhaps I did something wrong.