You provide no trustworthy benchmark for your claim that Go is slow, or that nim is faster than that. Many engineer hours have been put on the go GC and compiler
You can find a number of benchmarks with similar results, but I really like this one[0]. I didn't check all algorithms for differences, but just looking on mandelbrot bench - both are version 1 (without hacks or some manual loop unrolling thrown in) and both are implemented in semantically identical code. Nevertheless, Nim version runs 7x faster and, literally, on par with C.
You can find a number of benchmarks with similar results, but I really like this one[0]. I didn't check all algorithms for differences, but just looking on mandelbrot bench - both are version 1 (without hacks or some manual loop unrolling thrown in) and both are implemented in semantically identical code. Nevertheless, Nim version runs 7x faster and, literally, on par with C.
[0] - https://programming-language-benchmarks.vercel.app/nim-vs-go