Want to squeeze a bit more performance out of Ubuntu 25.10? If you have a modern 64-bit CPU and don’t mind the risk, you can use Ubuntu’s new amd64v3 packages – I’ll show you how.
Also known as x86-64-v3, these ‘optimised’ packages take advantage of instructions sets in the the v3 microarchitecture level. Not all 64-bit Intel and AMD CPUs support these, so first I’ll show how to check your CPU’s status.
But before rushing off to try things out, keep expectations in check.
Firstly, these variant packages won’t give you a major performance boost. Benchmarks show modest gains of ≤1% in everyday tasks on Ubuntu, with more pronounced uptick in workloads that involve intensive number-crunching.
To wit: if you mainly use Ubuntu to chat on Discord, browse the web and create cool things in Blender, you won’t notice any difference. And only packages in main have v3-optimised builds in 25.10, so other apps, DEBs, Snaps, Flatpaks etc don’t benefit.
More importantly, amd64v3/x86-64v3 packages in Ubuntu 25.10 are not as thoroughly tested as amd64 builds. You opt-in at your own risk; trying them helps Ubuntu developers will learn about problems and fix them to provide proper support in 26.04.
Still interested?
Check Your CPU Supports amd64v3
First, find out if your processor actually supports these optimised packages. While most 64-bit Intel CPUs from Haswell (4th gen, circa 2013) and AMD CPUs from 2015 onwards do include the relevant instruction sets, there are exceptions.
If you can’t remember what CPU you have, you can check the model/series in Settings > System > About and then search the web to check.
Or, you can save yourself the hassle and run this command in your terminal instead:
/lib64/ld-linux-x86-64.so.2 --help
Scroll to the bottom of the output and read the list.
If x86-64-v3 is listed as supported, you’re good to go. If it does not say supported next to it, this means your CPU lacks AVX/AVX2 and the other instruction sets required. Ubuntu’s amd64v3 packages will not work on your system, even if you force install them.
Installing amd64v3 packages on Ubuntu 25.10
Opting to use amd64v3 packages is more involved than, say, ticking a checkbox in a GUI app. This hassle is arguably necessary as these packages have not been tested as thoroughly as the standard versions Ubuntu 25.10 includes.
You’ll need to use the command-line to opt in.
Open your terminal and run the following command.
echo 'APT::Architecture-Variants "amd64v3";' | sudo tee /etc/apt/apt.conf.d/99amd64v3
This creates a new configuration file for apt in which you’re telling apt to fetch v3 variants of packages:
Now, update your package cache:
sudo apt update
You’ll be told 1k+ updates are available. These are amd64v3 versions of packages you already have installed. If you’re happy to continue, proceed to run sudo apt upgrade – if you want to back-out, see below.
When upgrading apt may say that packages are being downgraded. Don’t panic; they aren’t. This is described as a ‘cosmetic issue’ that will be addressed in Ubuntu 26.04 LTS.
Also, if you have enabled the proposed updates channel or added any third-party PPAs and APT repos, be mindful of the potential for package conflicts. As stated at the outset of this tutorial, you trial v3 packages at your own risk.
How to revert (if something goes wrong)
If you find that your system behaves oddly after migrating to these architecture variants, or you simply want to go back to the standard versions, it’s easy enough.
First, remove the apt configuration file you created earlier. While you can do this from the command-line, it involves running rm as root which isn’t something anyone should idly do.
Instead, use a Nautilus admin session:
nautilus admin:///etc/apt/apt.conf.d
In the folder, find the ’99amd64v3′ file and trash it.
Then, open your terminal and run:
sudo apt update --list-cleanup
After this, you can do a regular sudo apt update and upgrade. This should revert any packages that were upgraded previously to their standard amd64 versions. If not, you can reinstall them manually using apt install --reinstall.
Did it make a difference for you?
The architecture variant packages in Ubuntu 25.10 are somewhat experimental and currently only built for packages in the main repo. Canonical plans to build v3 packages in all of its reports in Ubuntu 26.04 LTS, though they will still remain opt-in
Don’t enable v3 packages on your device unless you’re comfortable troubleshooting potential issues and, ideally, reporting bugs upstream where necessary to help improve the quality and reliability of Ubuntu running on a x86-64-v3 base.
If you do give it a go, I’d love to know what impact you perceive it making to your workflow, so do leave a comment below!
h/t Shiba!