Symantec Messaging Gateway 9.5.x runs on a 32-bit Linux Operating System.
Symantec Messaging Gateway 9.5.x runs on kernel 2.6.x. The Linux kernel includes full PAE mode support starting with version 2.3.23. Also PAE is supported by the VMware CPU and by all processors since Pentium Pro/AMD Athlon.
What is PAE?
Physical Address Extension (PAE) is a feature to allow (32-bit) x86 processors to access a physical address space (including random access memory and memory mapped devices) larger than 4 gigabytes. x86 processor hardware-architecture is augmented with additional address lines used to select the additional memory, so physical address size increases from 32 bits to 36 bits. This, theoretically, increases maximum physical memory size from 4 GB to 64 GB - although the actual amount increased depends on the OS. The 32-bit size of the virtual address is not changed, so regular application software continues to use instructions with 32-bit addresses and (in a flat memory model) is limited to 4 gigabytes of virtual address space.
Applying this to SMG environment, the Operating System will be able to handle up to 64GB of Memory. Each process though (ecelerity, bmserver, ...) will only have access to 4GB of Virtual Memory.