They run at 40Mhz. This project [1] runs at 148Mhz using an open source "C/C++ to FPGA" tool to achieve realtime raytracing using integers/fixed/floating points (25Mhz with a 100% open toolchain [2]). Part of the project is currently funded by the Nlnet Foundation (the CflexHDL tool) and integration with the CERN AI tools is planned. Open source is important. DISCLAIMER: I'm author of the CflexHDL tool and the raytraced game, happy to answer questions.