Below is the final perf table.
Yes indeed, the perf differences are massive. This is because (1) the initial implementation/compilation was very much "unfinished" (2) this task is cpu intensive and quite sensitive to implementation - there is nothing generic about theses results.
| algo | compiler | opt_level | runtime | best vs. naive & not parallel |
|---|---|---|---|---|
| optimized | rust | release parallel safe b | 0.07 | 0.05 |
| optimized | rust | release parallel safe a | 0.17 | 0.11 |
| optimized | rust | release safe | 0.19 | 0.12 |
| naive | rust | release parallel unsafe | 0.32 | 0.21 |
| naive | gcc | -O3 | 1.54 | 1.0 |
| naive | rust | release v2 unsafe | 1.56 | 1.01 |
| naive | rust | release v3 safe | 2.2 | 1.43 |
| naive | rust | release v3b safe | 2.22 | 1.44 |
| naive | clang | -O3 | 2.27 | 1.47 |
| naive | clang | -O1 | 2.3 | 1.49 |
| naive | go | 2.34 | 1.52 | |
| naive | rust | release v4 safe | 2.62 | 1.7 |
| naive | gcc | -O2 | 2.9 | 1.88 |
| naive | rust | release v5 safe | 2.89 | 1.88 |
| naive | gcc | -O1 | 2.95 | 1.92 |
| naive | clang | -O2 | 4.35 | 2.82 |
| naive | gcc | 10.1 | 6.56 | |
| naive | clang | 11.53 | 7.49 | |
| naive | rust | debug v1 | 16.61 | 10.79 |
For ref this problem was a keygen search for a poker crate that is now published.