Ubuntu has added a new x86-64-v3 ‘architecture variant’ for Ubuntu 25.10, configuring its build infrastructure and package managers to support compiling and installing optimised packages.
“By making changes to dpkg, apt and Launchpad, we are able to build multiple versions of a package, each for a different level of the x86-64 architecture, meaning we can have packages that specifically target x86-64-v3,” Canonical’s Michael Hudson-Doyle says.
Canonical will offer v3-enabled versions of ALL packages in Ubuntu 26.04 LTS – but it won’t be the default baseline
Starting with Ubuntu 25.10, over 2000 packages are available in an “optimized form” for the “more modern x86-64-v3 architecture level”. These are available on an opt-in basis (i.e., users need to manually install a variant version).
Canonical plans to provide v3-enabled versions of all packages in Ubuntu 26.04 LTS, and says these will be fully tested.
Don’t panic if your 64-bit Intel or AMD CPU doesn’t support v3 as Ubuntu 26.04 LTS won’t be making it the default (‘baseline’).
But it wants people to be able to use Ubuntu 26.04 LTS with v3 – exactly how? TBD.
It may require users to manually install them; it may provide a separate installer image made from v3 packages; or it may use some clever mechanism in the installer that opts for architecture variants based on detected hardware capabilities.
What is x86-64-v3?
Although most modern Intel/AMD processors are 64-bit, they’re not all equal — and I don’t mean simply in terms of core count, transistor size, cache speeds, etc.
Not all 64-bit CPUs are equal – some won’t run v3-enabled packages
They differ in what instruction sets they support. Newer CPUs can include newer instruction sets. Packages can be optimised for those sets, which are grouped into microarchitecture levels based on the ones they support.
By default, Ubuntu uses plain amd64/x86-64 (v1), the broadest set. This is compatible with CPUs going way, way back (the CPU in my first-ever custom build PC was an AMD Athlon X2 6000+ and it can still boot Ubuntu 25.101).
Other Linux distros (further down) use v2 or v3 as their baseline. Devices with CPUs that that lack any of the required instruction sets can’t run it. CPUs with newer levels (like v4) are backwards compatible with older levels – so all v1 builds run on v4, but v4 can’t run on v1.
Linus Torvalds has chided Intel for chasing power-hungry instruction sets over general-purpose improvements
Packages optimised for instruction sets in x86-64-v3 (sometimes referred to as amd64v3) are available to test in Ubuntu 25.10. The most notable of these are SIMD AVX/AVX2 (Advanced Vector Extensions).
AVX/AVX2 let processors handle more pieces of data (256 bits) at a time, which (since computers compute) means potentially better/faster performance in operations that require a lot of data processing, e.g., crypto/encryption, scientific simulations, etc.
Linus Torvalds is not the biggest fan of Intel’s obsession with extending and adding instructions sets.
The Linux founder publicly chided Intel for its power-hungry AVX-5122, saying he feels the company is “trying to create magic instructions to then create benchmarks that they can look good on”.
“Stop with the special-case garbage, and make all the core common stuff that everybody cares about run as well as you humanly can”.
Is amd64v3 performance tangibly better?
While most CPUs made since 2015 onwards should support x86-64-v33, any tangible benefits in using optimised packages varies based on workload. Regular Ubuntu desktop users who switch to 64-bit variant packages won’t notice any tangible speed boost.
Regular Ubuntu desktop users who switch to 64-bit variant packages won’t notice any difference in performance
Ergo, this isn’t a “this one change makes your computer faster” deal (though your favourite tech YouTuber will no doubt suggest it is).
Back in 2013, Ubuntu released an experimental Ubuntu Server build that was optimised for v3. Testing at the time showed user negligible to minor gains.
Canonical mention performance boosts of 1% for ‘most’ v3 packages, higher for those doing number crunching thanks to AVX/AVX2’s ability to process 256 bits of data simultaneously.
On servers and high-performance computing (HPC) where workloads are typically data intensive, even a modest 1% speedup can mean a measurable difference in costs. For those, using amd64v3 package will have benefits.
But for most of us? Even if benchmarks show performance upticks in certain tasks/apps, that doesn’t translate to all tasks/apps being faster – nor does it mean that percentile bump will make a perceptible difference in everyday use.
Fashionably late to the AMD64-v3 party
Ubuntu isn’t pushing any boundaries in making optimised architecture builds available for amd64-v3. If anything, it’s late to market (albeit intentionally so).
Red Hat Enterprise Linux 10 (RHEL) moved to a amd64-v3 baseline earlier this year (and a v2 baseline in RHEL 9); openSUSE Leap 16 makes amd64-v2 its baseline (so it doesn’t run on most processors pre-2008; it provides select v3 builds in its repos too).
RHEL’s “forced” switch wasn’t without controversy but given its customers are enterprises, where every cent in performance matters, it is of less consequence.
If Ubuntu were to make v3 its baseline, rather than, as some distros do, dynamically offer the right packages for supported systems, it would leave older devices unable run newer Ubuntu versions, similar to how most RISC-V devices can’t run Ubuntu 25.10.
However, were that to happen… A lot of care would need to be taken, and a lot of sign-posting up-front done so that users aren’t left out in the cold.
If you want to try these new packages out — caveats apply — you can do so by following the steps in our guide.