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AMD EPYC Zen3 (Milan) Processors are not supported on Red Hat Enterprise Linux 7. Systems that have had their CPUs updated from Zen2 (Rome) to Zen3 (Milan) must also have their Operating Systems updated to Red Hat Enterprise Linux 8.3 or later, in order to maintain their certified/supported status by Red Hat.
AMD EPYC Zen2 Platforms that have had their CPUs updated from Zen2 (Rome) CPUs to Zen3 (Milan) CPUs.
While the AMD EPYC Zen2 (Rome) and Zen3 (Milan) processors are electronically compatible, Red Hat does not support in-place upgrades of Zen2 to Zen3 CPUs on systems running RHEL7. Furthermore, this processor is not supported in systems running RHEL7 at all. In order to maintain a certified/supported status, platforms where Rome (Zen2) CPUs are updated to Milan (Zen3), must have their operating system upgraded from RHEL7 to RHEL8.3 or later. New installs must likewise also be done with RHEL8.3 or later. OEMs and Vendors who certified these systems with the previous generation processors under RHEL7 should also undergo recertification with RHEL8.3 or later in order to retain their certified/supported status. Consumers should look for their platform on the Red Hat Hardware Certification Catalog:
To verify the system has undergone recertification.