./bin/perft/perft 7 "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
perft("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1")
depth 1 => nodes: 20, time: 0.000002 sec, n/sec: 10000000.000000
depth 2 => nodes: 400, time: 0.000006 sec, n/sec: 66666666.666667
depth 3 => nodes: 8902, time: 0.000072 sec, n/sec: 123638888.888889
depth 4 => nodes: 197281, time: 0.001522 sec, n/sec: 129619579.500657
depth 5 => nodes: 4865609, time: 0.036273 sec, n/sec: 134138587.930417
depth 6 => nodes: 119060324, time: 0.899482 sec, n/sec: 132365432.548956
depth 7 => nodes: 3195901860, time: 23.328347 sec, n/sec: 136996498.723206