It's fast as C in the same way Java and Go are as fast as C. To put it in more concrete terms, it's worst cases on the same order of magnitude as C at least for

It's fast as C in the same way Java and Go are as fast as C. To put it in more concrete terms, it's worst cases on the same order of magnitude as C at least for non-specialized usecases. Whereas dynamic languages are usually many orders of magnitude slower. Comparing "the speed of languages" is largely bullshit and you need to be comparing a specific problem. Crystal certainly has the genes required to be as fast as Go, and I think very few people are unhappy with Go's performance. Currently the major difference between Crystal and Go's single-threaded performance is the GC and thats not too bad. Parallelism is coming soon. You could say that Crystal and Go (by default) is faster than C (by default) for IO bound workflows because of how IO is handled in Crystal and Go. But most people look at micro-benchmarks which don't reflect the difficulty of achieving C's performance in C.