This is only a proposal and not a formal announcement at this time.
If you are running 64-bit capable hardware there are absolutely no valid reasons to be running a 32-bit operating system.
How would this work?
- Ubuntu GNOME 18.04 LTS will be the last Ubuntu GNOME release for i386. Because 14.04 and 16.04 LTS releases were supported for 3 years, 18.04 LTS will probably be supported for 3 years also — until April 2021.
- Ubuntu GNOME packages are currently built for 6 architectures (amd64, i386, armhf, arm64, ppc64el and usually s390x). GNOME packages will generally continue to be built for all architectures supported in Ubuntu where possible. Eventually, Ubuntu may stop building packages for some of those architectures but there is no announced date for that yet.
- Although packages are built for those architectures, Ubuntu GNOME will only provide install media for amd64.
- You will be unable to use update-manager or do-release-upgrade to update to any Ubuntu GNOME version newer than 18.04 LTS.
Why the change?
- Virtually all developers and bug fixers are using amd64.
Almost all users have amd64-capable computers (or will have them by 2021). amd64-capable computers have been sold since 2003-2004. Except for older versions of the Intel Atom, all computers sold for years support amd64.
- Performance using amd64 is faster in almost all cases than using i386.
amd64 does not use significantly more memory than i386.
- The Address Space Layout Randomization (ASLR) security feature is far more effective on amd64 compared to i386.