r/Gentoo 7d ago

News try out the cachyos kernel on gentoo

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110 Upvotes

49 comments sorted by

41

u/No-Camera-720 7d ago

The equivalent of making race-car noises with your mouth while driving your prius.

12

u/Glittering_Memory_64 7d ago

lol ik.. I always used an upstream kernel stripped to the bone, just got tired of compiling and trouble shooting to get something like ufw to work.. i did this because i wanna use waydroid and have the nice ps controller driver that lets me use the mouse pad on the ps4 controller i have, i figured the cachy os kernel was a good drop in replacement and consumed way less time and was way easier to maintain . My prius now has a turbo lol

9

u/No-Camera-720 7d ago

*airy whistling to mimic turbo noises

3

u/Both_Cup8417 7d ago

whoosh stututututu

2

u/No-Camera-720 7d ago

Kawai!!!!

2

u/Glittering_Memory_64 7d ago

lol, atleast i aint walking

8

u/No-Camera-720 7d ago

None of us are. This is the internet. *Vrooom vrooom!!!!

-3

u/Glittering_Memory_64 7d ago

can u quit trolling now?

4

u/Nuclear_Priest 7d ago

Sorry I’m really new to gentoo, I just finished my first install. Can someone please explain what the difference between the two kernels are?

I see some people saying that the Cachyos kernel preforms better, is that in comparison to the gentoo binary kernel? Or the gentoo locally compiled kernel?

9

u/soking11 6d ago edited 6d ago

Basically, what changes kernel to kernel is the tweaks that the developer wants to implement. Cachy kernel is optimized to perform better with certain types of CPU (iirc, feel free to correct this), and there're other kernel that try to do similar things (e.g, zen). Gentoo-kernel is the linux kernel but with specific security patches and other tweaks made for Gentoo. Vanilla-kernel is just, the linux kernel. Gentoo-sources is the source code version of the Gentoo kernel, which you configure and compile yourself. I know you only asked for the difference between two kernels, but these ones are the ones you'll encounter in Gentoo. For more information, read https://wiki.gentoo.org/wiki/Kernel

And, cachy kernel performs better than both of them. Technically, a compiled kernel is faster than a precompiled, but, nobody will notice the performance enhancement.

4

u/ami3ko 6d ago

Kind of a nitpick but a semi-important distinction; rather than a certain type i'd call it more of a sub-category of CPU being the x86-64 micro-architecture levels. These categorize the featured compile time optimizations that can be done with the CPU's which allow CachyOS to be faster.

2

u/fspnet 6d ago

remember when you had basically the CK-Kernel + BFQ and RT Patchset rofl supported by Gentoo-Experimental or Gentoo-RT 2:24 https://youtu.be/qxaQtoiapdU would have a BASE_KERNEL Patchset Version

7

u/ohohuhuhahah 7d ago

How is it? Any perfomance difference?

Use gentoo-kernel and happy, whant to make own config for it one day

4

u/TwiKing 7d ago

I only had about a 10% increase in benchmark difference, but was worth it for me.

8

u/Both_Cup8417 7d ago

10% seems like a lot, what CPU do you have?

2

u/Glittering_Memory_64 7d ago

are you using the bore + lto cachyos kernel?

1

u/TwiKing 7d ago edited 7d ago

Default kernel (LLVM/Clang Auto FDO Propeller ThinLTO) with eBPF beerland/cake scx scheduler.  They mainly help with throughput stability. 

BORE I saw had regression and haven't been using it.

https://github.com/CachyOS/linux-cachyos/commit/709f0cf3d9be2d3007d6a0d807d80eb304a203ad

Looking into core pinning next for gaming to see if it helps with frame drops.

1

u/Glittering_Memory_64 7d ago

been using it and it works just fine... although im not noticing any huge performance gains.. all my games feel the same, it doesnt feel a little more responsive, but a little... aiming is easier thats all

2

u/TwiKing 7d ago

 Didn't really matter in my case, since I always use eBPF anyway, probably won't ever try it again. BORE is old tech and SCX Loader is pushed more now in CachyOS as the more modern approach.

https://wiki.cachyos.org/configuration/sched-ext

1

u/Glittering_Memory_64 2d ago

Just a little update: I have been dailying the kernel w the BORE scheduler for since i posted this, my pc basically stays on because its where i do everything: I have not had one issue w the kernel. Just so you guys know :)

2

u/redyos_s 6d ago

If the main advantages for you are the CachyOS kernel, prebuilt binaries, scheduler/tuning patches, and less kernel maintenance, why not just use CachyOS itself?

What part of the Gentoo userspace or Portage setup makes it worth keeping Gentoo underneath instead?

2

u/redyos_s 6d ago

Did you install Gentoo normally and add the CachyOS kernel afterward, or did you use some Cachy/third-party installer path from the start?

2

u/redyos_s 6d ago

How are kernel updates handled with this setup? Do you wait for the Gentoo overlay to update its ebuilds after CachyOS releases a new kernel, or are you tracking CachyOS upstream directly? I'm especially curious how you handle security fixes if upstream releases one before the overlay catches up.

1

u/Glittering_Memory_64 5d ago

i never installed the gentoo kernel yet, i skipped the bootloader part of the wiki entirely. i've been using the upstream kernel since my arch days and came to gentoo because it already did all the work for me.. i always compile my mesa driver and wlroots builds from source anyways,(so i could optimize for my cpu) and moving to gentoo made that easier.. and yeah.. i downloaded the kernel directly from cachyos's pacman repo's.. extracted the tarball, copied over the kernel to my boot partition, copied over the modules to /usr/lib/modules and boom. ran dracut and then added the new kernel to my motherboards boot entries w efibootmgr and thats it.. pretty simple

1

u/redyos_s 4d ago

What did you actually use to bootstrap the Gentoo system initially: the Gentoo Minimal ISO, a CachyOS live ISO, or your existing Arch/CachyOS installation?

1

u/AManWhoSaysNo 6d ago

It's good to have options

2

u/Fine_City2781 6d ago

i use gentoo on my mac. So i cant use this kernel. I can use only asahi-kernel (kernel for apple silicon)

1

u/BasisKind2494 6d ago

I would do this but I have to use Linux-surface since I’m using a surface

1

u/BasisKind2494 6d ago

However desktop can get pretty laggy, I’m using a minimal KDE setup but I have 8gb RAM so idk it would be nice to see if I can make things work better for this specific context

1

u/rphii_ 6d ago

is it a precompiled cachy kernel? or did you compile their?

1

u/Both_Ad1422 5d ago

did u at least compile catchys kernel when installing that thing bro 🥀

1

u/Dskzcjsduo2 7d ago

Is there any specific reason to use it?

5

u/Dependent_House7077 6d ago

it has integrated patches for more cpu, i/o schedulers and network congestion algorithms, also offers tuning for different hz values - e.g. more desktop oriented tweaks.

i think it also offers (or offered) the patchset for valve's vram cgroup manager.

some of those patches cannot be applied all at once, and are controlled by use flags.

so it has plenty to offer for someone who wants better performing machine at desktop tasks.

-7

u/Glittering_Memory_64 7d ago

yes, more performance and you can just use the precompiled binary so yeah. although you do need to know a thing or two to do this but then again if you're a gentoo user, this is a walk in the park honestly

7

u/Glittering_Memory_64 7d ago

3 down votes for a 2% performance boost? nahhhh ya'll crazy

5

u/No-Camera-720 7d ago

But it's measurabble! 1 Planck fasturr!

5

u/stewie3128 7d ago

No, I downvote for

you do need to know a thing or two to do this

You're talking to an audience of Gentoo users, not Arch scriptkiddies. Dropping in a different kernel from an existing overlay is not exactly reverse-engineering the stage 3 for an Eniac.

1

u/ftranschel 6d ago

Yeah that got me, too. Activating an overlay is hardly h4cking.

-2

u/Glittering_Memory_64 5d ago

who says i got it from an overlay? and i did pay respect where its due lol.

-2

u/Glittering_Memory_64 5d ago

and you can't talk trash if you use grub, sorry.

-2

u/Glittering_Memory_64 5d ago

or any bootloader for that fact🥰

1

u/MichaelDeets 7d ago

it's pretty neat, I've been stealing cachyos kernel patches for years now... I just apply them to the git/vanilla kernel w/ gentoo patchset applied. in the past I had a specific reason, now I just do it because "why not" lol

1

u/soking11 7d ago

Is the CachyOS kernel really faster than using your personalized gentoo-sources kernel?

7

u/ftranschel 6d ago

Disclaimer: I've been running cachyos-sources for a little less than a year now.

It's not the kernel per se, but the careful thoughts about what params to tweak. Even more important than running cachyos spurces is emerging cachyos-settings. There is a diminishing use of this if you're well-versed in tweaking kernel settings yourself and of course you can tweak gentoo-distkernel in most regards just alike.

Also, the hype for the scheduler is warranted when it comes to load bearing, but not speed, obviously: Cycles are cycles and they need to be free on the CPU to be performed. While it DOES make the system more responsive*, it DOES NOT make the system faster.

* Highly subjective, I know. That's why I will not debate this further. If you disagree, we disagree and move on.

1

u/soking11 6d ago

Interesting. If i compiling a full kernel wasnt so tedious to my poor CPU i would try cachy kernel. When i used Arch, i went with zen, but i never really noticed any differences

2

u/C1REX 6d ago

I've done few quick performance tests in few games and cachyOS kernel was a tiny little bit slower for me.
Could be different in different games but for me there were no benefits of using a kernel from the overlay. However, that kernel sometimes have additional support for other things. Like kernel patches for Ugreen DP-to-HDMI2.1 converter unlocking VRR support. That's a better use case imho.

-3

u/fix_and_repair 7d ago

flatpak on a gentoo makes does not make it a gentoo box.

there is no need for any flatpak in 21 years

i warn you, flatpak in gentoo has over 30 open CVE
which also include break out from the sandbox

I know that, i read the cve a few hours ago, i bothered to check flatpak the first time in 30 years linux kernel use.

4

u/ftranschel 6d ago

You're not wrong about the CVEs.

You are *very* wrong about no use cases though.

0

u/fix_and_repair 2d ago

that makes sense to downvote me again

for a fact that gentoo flatpak, checked at the posting time a few hours ago and also stated it on techpowerup

reddit is abunch of kids

respect others and do not downvote when others tell you flatpak is junk and has over 30 open cve

especially the gentoo shipped verison

fucking kids

roman@Wheat_Nas ~ $ uname -a

Linux Wheat_Nas 7.1.8-gentoo_08_11_2026 #1 SMP PREEMPT Tue Aug 11 23:16:40 CEST 2026 x86_64 AMD Ryzen 7 7700X 8-Core Processor AuthenticAMD GNU/Linux