RHEL AS 3.0 support on AMD64

[Arthur Perry]

Hello,

I have a quick question about support on RHEL AS 3.0 for X86_64.
The support matrix claims that a max of only 16G of RAM is supported for
X86_64, but a much larger amount is supported for the x86 platform.

Is there a reason for this cutoff at 16G for x86_64?

I just need some details from the folks at RedHat to explain this, without
making my own assumptions.

Thanks in advance!