The iPhone 8, 8 Plus, and X will each support 24 different LTE bands across the globe. European iPhone SKUs, however, will be shipping with slower Intel modems that could force Apple to limit maximum download speeds across all iPhone SKUs to the lowest common denominator.
https://www.notebookcheck.net/The-iPhone-8-in-North-America-may-have-faster-LTE-modems-than-the-international-versions.251884.0.html