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Comment by quirino | Hacker News Reader

Maybe I should include a warning that it is pretty slow.

I'm using my own SHA256 implementation in C++, and it is at least 100 times faster than the JS one. I've measured it to be about as fast as the one on the Go standard library.

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Anyone who stumbles into your SHAllenge ought to know that JS isn't going to be really competitive, so I think you're good. A warning might encourage them to delve a little deeper. I like that it makes it very accessible.

I assume anyone with knowledge about GPU hashing and the will would be able to steal the top spot very quickly. Assuming seletskiy isn't already that guy. I don't have a good grasp on the compute difference between 8-9 0s and 10 0s in a reasonable amount of time.

Assuming hashes are random (which is a reasonable assumption, considering it's sha256), every extra leading zero cuts the probability of success in half, meaning double the candidates searched to find a matching value. So each additional leading hex 0 would take on average 16x longer than the last.

I kept at it mostly as an exercise to test different compiler options. I found that a miner implemented in C runs in 1/5 the time of a Perl script (but at ~10 times more lines of code). Also, compiling with "-march=native" reduces the run time by ~10%, and concatenating all C files together to compile and link in a single step saves another ~0.5%.

I felt like I got enough out of this exercise and don't need to burn more CPU cycles on it :)

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