The 14.04 release notes contain the following sentence:
X32 ABI support (64-bit mode with 32-bit pointers) was also introduced.
I think this deserves a bit more explanation. When you use a search engine to find out more about "x32 ABI", you may find a Wikipedia article at best, but mostly Phoronix and Slashdot, which don't seem to be very useful.
I'd like to see some insightful answers on:
- How or what of x32 ABI is currently implemented in 14.04?
- Is it enabled by default in 14.04 64-Bit or are there any additional steps needed to setup x32 ABI?
- What components or what software can use x32 ABI?
- Are there actual benefits on a machine/installation running x32 ABI?
- How is the memory consumption in comparison with default 32-Bit and 64-Bit installations?
Ideally the x32 ABI should have brought the best of both worlds together: Most of the speed improvements of x86-64 and lower memory consumption for users on older 64-Bit capable hardware that didn't have a lot of RAM.
Edit 2020-08-25: I recently noticed when running Ubuntu on a Chromebook through Chrome OS Linux App Beta (a special VM in Chrome OS that runs LXD which by default runs Debian but it can run Ubuntu, Fedora, Arch Linux and others) that it has a /libx32 folder. May be this question needs to be reviewed/revised or asked again. I will think about that.