Comment 7 for bug 156804

>It's a known fact that 32-bit Linux only supports around 3.2 GB of RAM.
???

With PAE and HIGHMEM_4G/HIGHMEM_64G enabled and compiled for i686 or higher, a 32-bit Linux can see 4 GB resp. 64 GB without problems.
(One could of course argue that these kernels are not "pure" 32-bit)

In some PAE articles I fell over months ago, there were success reports for using 8 GB on some 32bit servers (HP or Dell I believe), and I can confirm 4 GB for a pure 32bit Dell 2600 running SuSE 9.2 with a kernel called 2.6.8-24.25-bigsmp.
Obviously, cracking the 4 GB barrier requires certain things (address lines, PAE support, ...) from CPU, mainboard, memory and BIOS, but just a obviously there are 32bit servers fullfilling these requirements.

And we still want HIGHMEM_64G for -generic kernels for using it on Desktops and Laptops, because the application situation for 64-bit is still far from satisfying, due to some large firms' ignorance (which might be broken by Microsoft's 64-bit-only policy for W2k8+).

A precompiled firefox-ia32 package (and a bunch of firefox-plugin-*-ia32 packages) for the amd64 distro could provide a workaround for the most annoying lacks of amd64 ubuntu, but the increased memory usage of 64-bit binaries still recommends using a 32-bit distro.