I suggest do not use -t option with cpuminer.. it will automatically the set the best number of mining threads. Normally no of logical processors and not cores. You can find your processor details in Task manager in win OS.
I'd suggest to use -t option for achieving fixed performance; at least for large amount of cores assigning -t parameter higher than physical cores count does not increase the hashrate. Again one must keep in mind the cache size.
To the benchmarks table: double Xeon E5-2683 v3, 28 cores, 28 threads -> 3.4 kh/s.