Enabling more than 3 gigabytes of RAM in Linux
Doubtless, most everyone knows this, but since I’m just now crossing the 1 gigabyte line in my latest computer, I was left blissfully unaware.
In Linux, the normal, 32-bit kernel can see a maximum of 3 GB of RAM. To get it to see more one must enable Physical Address Extension (PAE) in the Linux kernel.
Apparently, this is enabled by default in most newer distribution, but not on the Sabayon installation on the hard drive yanked from my old Ultra 20.