// Suites of benchmarks consist of a name and the set of benchmarks in
    // addition to the reference timing that the final score will be based
    // on.  This way, all scores are relative to a reference run and higher
    // scores implies better performance.

For complete clarity, see also the lines

https://github.com/Nubisa/jxdocs/blob/master/benchmarks/core...

The score is (arbitrary reference constant) / (geometric mean of runtime). Bad performance ==> longer runtime ==> lower scores.