High-speed x-ray reflectometry dataset for PTCDI-C8 molecules."High-speed x-ray reflectometry for characterization of thin film growth at high deposition rates"David Schumi-Mareček, Andrew Nelson, Erwin Pfeiler, Maximilian Eder, Florian Bertram, and Stefan KowarikPhys. Rev. B - Accepted 4 September, 2025DOI: https://doi.org/10.1103/xxx9-8tk2 We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out at PETRA III beamline P08. We thank Federal Ministry of Education and Research (BMBF) of Germany for funding Eiger2 1M detector via ErUM Pro 05K19FK2 (Murphy, CAU Kiel).