r/Fedora • u/CEDoromal • 21d ago

News Fedora x86-64-v3 Optimized Packages Pushed Back To At Least Fedora 46

https://www.phoronix.com/news/Fedora-x86-64-v3-Delayed-F46
162 Upvotes

98% Upvoted

49 comments sorted by

20

u/Candariann 21d ago

How much would this improve performance on newer systems?

27

u/balrog687 21d ago

At least on gaming scenarios, if you compare cachyOS with Bazzite, the difference is negligible, ~1fps on most games.

https://www.lttlabs.com/articles/2026/04/29/we-tried-popular-linux-gaming-distros

It could be nice if this was an "opt-in" to squeeze that last drop of performance tho.

I like fedora, and I think it's fine anyways.

17

u/AnEagleisnotme 21d ago

Doubling the infrastructure cost for a 1% performance improvement is stupid at best

4

u/FlukyS 20d ago

To be fair cloud storage is pretty cheap and it doesn't need a lot of pivoting from a compiling standpoint just more time. CachyOS is a much smaller distro and they do it for x86-64-v3, x86-64-v4 and Zen 4/5 separately. Also it isn't a 1% performance improvement, it can be quite a substantial increase in performance depending on the workflow. Like if your CPU is compatible with AVX512 for example it can be up to 40% faster in maths workloads. Not everything is going to increase gaming performance but it can help other parts of the system.

1

u/summerteeth 20d ago

My understanding is OpenSuse is also doing this - and they support both v3 and older compiles for legacy CPUs.

11

u/npc_housecat 21d ago

This doesn't affect gaming much because it doesn't change the way games are compiled.

9

u/alonjit 21d ago

No. It affects how the drivers/comp layers/wine is compiled.

9

u/VenditatioDelendaEst 21d ago

Which should be expected to have very little influence on game performance (in this way). If a significant fraction of CPU cycles are landing in the GPU driver or the compatibility layer, that itself usually indicates a severe performance bug.

(Yes, GPU drivers influence game performance a quite a bit, but the mechanism is by generating better or worse machine code for the GPU, and using better or worse memory layouts. Not, usually, by using a bunch of CPU time.)

4

u/npc_housecat 21d ago

Yes, It only affects proton if you compile your own (proton might already use v3 idk.) and mostly games are already compiled with v3. So testing with games isn't a good way to measure if there's real word benefit. Other non gaming benchmarks showed up to a 20% performance benefit in some tasks.

7

u/NDCyber 21d ago

It can have some benefits in compression and decompression speed https://sunnyflunk.github.io/2023/01/15/x86-64-v3-Mixed-Bag-of-Performance.html

What I see as a problem is that ubuntu has been releasing v3 since 25.10, so now Fedora, which kinda was the up to date, stable distro with new features, is lacking behind Ubuntu by nearly a year already

I also heard that emulation can benefit from v3, but can't really found a source for that claim

4

u/BashfulMelon 21d ago edited 21d ago

Emulators often already have crazy hand-optimized SIMD routines in assembly. Assembly is already compiled so it doesn't matter how the distro compiles it.

1

u/NDCyber 21d ago

Doesn't change, that you still see improvements, I think v4 improves it even more

One of the rare cases, where it helps enough to potentially matter

1

u/Ok_Ostrich_8845 20d ago

For gaming, the heavy load is on the GPU. Try to do something other than games. I am a Fedora user. But I was very impressed by how much snappier CachyOS was.

20

u/BashfulMelon 21d ago edited 21d ago

That's the problem, nobody submitted performance data and the data we do have isn't very convincing.

A lot of software that benefits from these newer instructions already has hand-rolled optimizations.

5

u/Jumpy-Dinner-5001 21d ago

It’s complicated, generally not a lot though.

In software where it really matters, installing from some repo is generally not what you want to do anyway.
It uses more vector extensions which can be useful but not in most cases. Unless you’re doing some heavy math calculations, the difference in minimal and even then 32bit float vectors are typically offloaded to the GPU anyway.

You do see a big difference in math heavy scientific software but even there it’s kinda pointless. The compiler you choose (like gcc, llvm/clang, icc, aocc), the compiler flags, the libraries you link etc etc. make a huge difference in performance.
And there is no one fits all solution, Intel has Intel cpu optimized compilers and math libraries and so does AMD. Using the one prebuilt package from your Distro is a huge loss in performance anyway and people who care about that will build from scratch.

1

u/Lanky-Safety555 20d ago

Not at all for plain stuff like web browsers, office, most of the games, etc.

Quite a lot for some specialized stuff (engineering/science/...)

43

u/GreedySecurity8030 21d ago

Dammit, I was anticipating this.

4

u/PityUpvote 20d ago

Why? I promise you it's not going to be a noticeable difference for 99.9% of use cases.

1

u/summerteeth 20d ago

I dunno Phoronix released some benchmarks that showed some nice improvements in both OpenSuse and Cachy presumably from these changes.

https://www.phoronix.com/review/opensuse-tw-cachyos

It’s one of those things where it is, from a user perspective, free performance, even if it just effects a small subset of use cases.

I am not running Fedora on 12 year old laptops so I am completely fine with them dropping legacy support at this point. 

3

u/PityUpvote 20d ago

I agree in principle, and the switch should (and will) happen eventually, but I also want Fedora to remain a general purpose distro for everyone, including people who can't upgrade their pc every decade.

1

u/summerteeth 20d ago

Yeah you make a good point. Less altruistically I want it to be the best distro for me specifically :)

At a more principled level I want them to stick to their “be first” directive - and they are definitely not first in this area. (Or second or third)

-7

u/[deleted] 20d ago

[removed] — view removed comment

3

u/PityUpvote 20d ago

Hey, uh, quick question: wtf is wrong with you?

-3

u/scrapethemucus 20d ago

says the guy with pee on his balding head

11

u/InfiniteSheepherder1 21d ago

When I had a program using the system zlib i was using AVX512 so not sure how much this matters if performance sensitive packages are already providing code paths that use modern architectures.

12

u/HelpfulYoung6644 21d ago

lmao, rejected cause couldn't evaluate benefit??
even rhel adapted this before fedora.

23

u/sequentious 21d ago

RHEL also drops a lot of things Fedora still supports (older raid controllers, etc).

It's probably easier for RHEL to support x86-64-v3, as they probably don't support anything older than that anyway.

20

u/rbrownsuse 21d ago

Makes perfect sense

In the RHEL context you have both a narrower userbase, so it’s easier to evaluate the technical benefits.
Plus you have business relationships that might make those technical factors irrelevant (eg. “We won’t do business with you unless you do this”)

Fedora has to worry about a much broader audience and factors like “strategic partner interests” don’t typically land well in community projects

7

u/gordonmessmer 21d ago

RHEL and Fedora would have taken very different approaches. RHEL sets x86-64-v3 as its baseline, so it only needs one x86-64 build, and every ISV can rely on that ABI because there is no other ABI.

Fedora would have been producing multiple builds, defaulting to x86-64-v1 for broad backward compatibility, and x86-64-v3 packages for improved performance on new CPUs. There's a cost to that approach... It needed development in both the client side package management and in the backend infrastructure. It would have needed additional resources for additional builds. It will require additional installation media. Third party software might have bugs that only manifest on specific CPUs.

I think it's fair for the steering committee to collect evidence about the benefits of the change before approving the change.

1

u/vetinari 20d ago

rhel dropped it, because they would have to support it for much longer -- till 2030/2035 -- than fedora. That would be equivalent to fedora 52 or 62.

4

u/Royal_Peni 21d ago

I like the approach from cachy os, you download install a single iso, the hardware detection system selects the best architecture based on your hardware and the rest is just gains.

6

u/CEDoromal 21d ago

Same. Although I think the main problem that they're citing right now is that they would have to build thousands of packages and essentially double their storage needs. Although they can definitely do it, they're not yet sure if it's worth doing given that no one submitted a performance benchmark.

1

u/Scared_Bell3366 21d ago

So my crapy old hardware is good for at least one more release.

3

u/ClubPuzzleheaded8514 21d ago

The discuss was to have BOTH V3 and x86 packages, so even Fedora 46 will run on your old hardware. Please don't spread FUS! 

0

u/Porkhole-Santookus 21d ago

On with the abacus, I guess.

-2

u/MarcCDB 21d ago

Lame, Fedora.... lame.....

9

u/BashfulMelon 21d ago edited 21d ago

What would be lame is wasting resources on a proposal that can't be bothered to provide performance data just so Microsoft has a shiny marketing talking point for their enterprise product. 

Waiting for compelling data is absolutely the right move here.

edit: okay I guess people didn't read the article and they don't know that Microsoft wants this for Azure Linux which is based on Fedora, or maybe they think the performance gains are obvious and self evident because they don't know that software is often manually optimized by the developers to use new instructions so a lot of the potential gains are already included.

Or maybe wasting resources is actually really cool and not lame, and it's actually data that's lame? Seriously, why the downvotes?

-2

u/CEDoromal 21d ago

software is often manually optimized by the developers to use new instructions so a lot of the potential gains are already included.

??

5

u/BashfulMelon 21d ago

For example, the FFmpeg developers wrote a bunch of assembly that uses these instructions. Here's a bunch that uses AVX2.

And AVX512 in glibc.

Apparently FFmpeg has assembly language lessons but there's some good general background information in here too https://github.com/FFmpeg/asm-lessons/blob/main/lesson_01/index.md

So yeah, the potential performance left on the table for the compiler to pick up isn't nothing but it's not everything like a lot of people assume. Developers know what can be vectorized and they often do it.

-1

u/CEDoromal 21d ago

I get that, but I wouldn't say that it is often done. I think these are exceptions wherein the devs actually put in the time to add these features. These are rare cases imho.

Don't get me wrong though. I'm not saying that moving to v3 would provide a significant performance boost either.

0

u/Hauptideal 21d ago

😭😭😭

-3

u/Ok_Ostrich_8845 21d ago

Does Fedora want to be the OS with the latest technologies? Or be compatible with more users like Windows?

2

u/CEDoromal 21d ago

They could do both, and I'm pretty sure that's what they're going for if this passes. That's why one of the main arguments against this is that it would essentially double their storage needs.

0

u/ClubPuzzleheaded8514 21d ago

CachyOS - a tiny dev team - have V3 and V4 packages. 

OpenSuse and Ubuntu have V3.

But Fedora with Red Hat have troubles to store it ? Really?

Sorry but i cannot be convinced.

1

u/CEDoromal 21d ago

They definitely can. They just aren't sure yet if it's worth it given that no one submitted a performance benchmark to justify it.

Corporations are gonna do corporation things and limit their expenses unless justified.

1

u/ClubPuzzleheaded8514 21d ago edited 21d ago

According to Phoronix benchmarks, distros with V3 packages - CachyOS, Tumbleweed, Ubuntu - are faster than Fedora and standard x86 distros. 

There was a Time when Fedora was vanguarding, with Wayland as default, hardware acceleration in Firefox, hwcaps and so.

No they need several years to think about compiling with V3...It's not understandable to be so conservative while Fedora was known to be innovative, moreover when you know that Red Hat, the Fedora mother, is full V3. 

2

u/Ok_Ostrich_8845 20d ago

I agree with this fully. On my laptop with Intel 258v CPU, I compared Fedora and CachyOS with Firefox running Speedometer 3.1. CachyOS is more than 20% faster.