A possible 2020 Apple iMac refresh device has been discovered on Geekbench with some surprising components: An unknown Intel Core i9-10910 processor and an unannounced AMD Radeon Pro 5300 desktop GPU. There has been speculation before of an upcoming refreshed 27-inch iMac being configured with a fast Comet Lake Core i9 CPU.
https://www.notebookcheck.net/Potential-2020-Apple-iMac-refresh-with-unknown-10-core-Intel-Core-i9-10910-CPU-and-AMD-Radeon-Pro-5300-desktop-GPU-spotted-on-Geekbench.479582.0.html