Note that the benchmark doesn’t take into account the number of solutions produced on each run (which is most likely to be 2 but may be other values), and the fact that solutions are checked by the difficulty filter as they are produced. In particular, runs that produce more potential “partial solutions” will take longer, but will also produce more valid solutions before the difficulty check. (Almost all partial solutions that pass the IsProbablyDuplicate test, which is quite fast, are valid solutions.) I think we’re going to write another throughput-oriented benchmark which would give a better indication of mining performance.