Hi everyone,
I’ve seen some discussion suggesting that Ubuntu 26.04 might require a CPU that supports the AVX2 instruction set. Is this actually true?
I’m trying to understand if this is an official, confirmed requirement (like the one introduced for 24.04 with SSE4.2), or just a rumor. Would a system with an older CPU that lacks AVX2 (for example, a Kaby Lake Pentium like the G4560) be completely unable to boot or install the final stable release of 26.04?
If it is true, could anyone point me to an official announcement or a bug report where this decision was made? I’d like to understand the reasoning behind it.
Thanks for any clarification!
Can you cite some discussions? Thanks.
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I saw these rumors scattered in different places — forum comments, tech chat groups, etc. I didn’t save the links at the time. On the other hand, DevBytes reported that Ubuntu 26.04 will support AVX2.
These two pieces of information conflict with each other, which raised a question for me: does “support AVX2” just mean a new feature, or does it mean that older CPUs without AVX2 won’t be able to boot 26.04 at all?
The oldest device I use in my install testing is a HP Compaq from 2007, ie. Core2Duo processor (c2d-e6320) .
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Thank you very much for the real-world test. If your Core 2 Duo can run it, then my Pentium G4560 should be fine as well. It seems that processors without AVX2 can still run 26.04 after all.
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In my ignorant opinion Ubuntu 26.04 LTS will still run on older CPUs provided the user does not run an application that is designed to make use of AVX2 extensions.
This is what I get from Google AI
Top Applications Requiring or Using AVX2
- Adobe Creative Cloud (2024 and later): Recent versions of Adobe apps, including Photoshop, Lightroom Classic, and Acrobat, require AVX2 for installation and operation.
- Video Encoding/Transcoding: Tools like Handbrake and various H.265/HEVC encoders use AVX2 to significantly speed up video rendering and conversion.
- 3D Rendering & Modelling: Software such as Blender and Cinema 4D utilize AVX2 to speed up vector math in rendering.
- Gaming: Many modern games built on engines like Unreal Engine 4/5 use AVX2 for physics simulations and game logic.
- AI & Machine Learning: Applications that utilize image-to-video generation, such as tools that make images “talk” in live video, often require AVX2 to operate efficiently.
- Audio Production: Digital Audio Workstations (DAWs) and specialized plugins (e.g., from Waves or Native Instruments) use AVX2 for complex audio processing.
Please do not start rumours about Ubuntu.
My modest OEM laptop runs Ubuntu 26.04 without any difficulty. On the other hand this machine would be of a too low specification to do any of the tasks that AVX2 extensions would be useful for.
Intel has an application that will test if your Intel CPU supports AVX2 extensions.
Does my INTEL CPU support AVX2 extensions?
As I see this matter, the issue is not the operating system but the hardware being able to fully utilize the features of the programs/applications. No change there! That has always been the case with computers and computer programs.
Regards
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Can you point to some documentation that does make it an actual requirement, as in Ubuntu 24.04 won’t run on CPU’s without SSE4.2? Because I haven’t heard of it and couldn’t find anything in the release notes.
Also, don’t confuse “support” with “requirement”. Running apps that have runtime-enabled SSE4.2 optimizations will work just fine without that extension, albeit (probably) much slower.
I think the discussions being referenced originally might have come from there being an amd64v3 architecture variant for 26.04 ( see Introducing architecture variants: amd64v3 now available in Ubuntu 25.10 where architecture variants were originally introduced with 25.10).
If you opt in to install the amd64v3 architecture variant on Ubuntu 26.04. Then you’ll need the AVX2 instruction set. But as far as I’m aware that is a totally optional thing to do. And if you stay with the default amd64 architecture, then you’ll not be running OS packages that are built to require AVX2.
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@alavaliant-r
Thank you for providing that link. It brings greater clarity. The words that jump out at me are “packages” and “archives.”
The architecture variants are not variants of Ubuntu but variants of packages or applications in the Ubuntu archives or repositories.
For the upcoming 26.04 LTS release, we will rebuild amd64v3-enabled versions of all packages and test them in the same rigorous way as we test every other Ubuntu package.
If your machine is supported, and you’d like to try out the new packages, you can opt-in to the x86-64-v3-enabled packages.
Then I read this:
If you do install the available amd64v3 versions of packages, you will not be able to transfer your hard-drive/SSD to an older machine that does not support x86-64-v3
That only makes sense to me if it is packages that are part of the Gnome Desktop Environment and User Interface that are being rebuilt as amd64v3 architecture variants. That could be the case.
Regards
You will still be able to mount the hard-drive/SSD with pre-amd64v3 CPU’s alright, but you cannot run the software that’s on it, because the CPU will lack AVX2, for instance, and what other instruction set extension are included in amd64v3.
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I agree with you.
Going back to the claim that was made when this topic was opened - Ubuntu 26.04 LTS will run on those older CPUs provided these amd64v3 architecture variant packages are not the default packages in Ubuntu. I do not think that they will be until those older CPUs are no longer around.
At this time we do not know how to revert the installation of these amd64v3 variant packages. Except to recommend a re-installation of Ubuntu. Canonical is still working on that part.
We should be careful about recommending activating amd64v3 variant packages unless we are willing to hold the hand of the user if things get broken.
Confirm that the CPU has these AVX2 extensions before making any recommendations about AVX2 and architecture variants.
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You’re overthinking it. That’s what “opt-in” means.
The same way they got enabled in the first place; select the base amd64(v1) and apt update && apt upgrade. Essentially, you do the steps to enable them in reverse.
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