The current Red Hat Enterprise Linux 5 (RHEL5) certification limits for x86_64-based systems are 64 total processors (including hyper-threading) and 256GB maximum memory per http://www.redhat.com/rhel/compare/. The BladeSymphony 2000 IA-32 Server Module GVAE57A1 supports up to 128 CPUs and 1TB of memory on the x86_64 (64 bit) architecture; the system therefore required additional testing beyond the normal certification requirements.
Note that x86 (32 bit) systems are limited to 32 CPUs (including hyper-threading) and 16GB of memory.
Red Hat Enterprise Linux 5
The Hitachi 2000 IA-32 Server Module GVAE57A1 with 8 CPU sockets supporting up to 128 CPUs and up to 1 TB of memory.
The BladeSymphony 2000 is certified on Red Hat Enterprise Linux 5.4 with RHSA-2009-1670-1. This Red Hat Enterprise Linux errata includes the minimal set of changes required for Red Hat hardware certification of the reference platforms. Later errata or updates and may be required to fix specific additional problems.