The A11 hexacore SoC packs 2 high-performance Monsoon cores, 4 energy-efficient Mistral cores and a 3-core GPU. The single-core test results are higher than what most Qualcomm chips can score in multi-core tests.
https://www.notebookcheck.net/iPhone-X-A11-SoC-benchmarks-leaked-before-official-presentation-event.248308.0.html