Which Update release and architecture of Red Hat Enterprise Linux 4 are required for a Sun Fire X4600 M2 system equipped with AMD Opteron processors codenamed "Barcelona" and/or more than 64GB of RAM?

Red Hat Enterprise Linux 4 Update 6 or newer, x86_64 architecture, is required when running Red Hat Enterprise Linux 4 on a Sun Fire X4600 M2 equipped with AMD Opteron processors codenamed "Barcelona". The same update release of Red Hat Enterprise Linux 4 is also the minimum requirement if you wish to run greater than 64GB of RAM on this system.