It seems that AMD has been collaborating with FreeBSD to develop a complete FreeBSD AMD IOMMU driver. This would better support the Epyc CPUs on FreeBSD and improve support for more than 256 CPU cores. Hopefully whatever they work on is FOSS. https://www.phoronix.com/news/FreeBSD-Q2-2024-Improvements More of what FreeBSD has planned can be found in their second quarter status report for 2024: https://www.freebsd.org/status/report-2024-04-2024-06/