CachyOS COPR Repository for Fedora (x86_64-v4)

Goodies from CachyOS ported to Fedora, highly optimized for modern CPUs.

Warning

Hardware Requirement: This repository is strictly compiled for the x86_64-v4 microarchitecture (requires AVX-512). If you install these kernels on older hardware (v2 or v3), your system will experience a kernel panic on boot.

If your CPU does not support v4, please use the original upstream project which provides v3 and v2 kernels.

• Kernels
  • Features
  • Installation Instructions
    • Default Kernel
• Addons
  • CachyOS-Settings
  • scx-scheds
  • scx-manager
  • ananicy-cpp

🐧 Kernels

We offer a variety of CachyOS kernels ported and heavily optimized for Fedora (43, 44, Rawhide) and EPEL 10:

• kernel-cachyos-v4 - 1000 Hz kernel with BORE scheduler
• kernel-cachyos-lts-v4 - LTS kernel with BORE scheduler
• kernel-cachyos-rt-v4 - Real-time kernel with BORE scheduler

All variants are available compiled with either standard GCC or LLVM-ThinLTO (-lto packages).

📢 Announcement 2026/02/23

We have removed the support for prebuilt Nvidia drivers with the kernels. The reason for this decision is a mismatch of release schedules between RPMFusion, Fedora and CachyOS. Following this decision we advise users to switch to either RPMFusion or Negativo17's Nvidia drivers.

🌟 Features

• Strictly optimized for x86_64-v4 CPUs across all builds (including LTS).
• Target OS Support: Fedora 43, Fedora 44, Fedora Rawhide, and EPEL 10.
• Choose between GCC and LLVM-ThinLTO builds.
• BORE scheduler with sched-ext support.
• AMD P-State Preferred Core, AMD CPB Switch and upstream amd-pstate enhancements.
• Cachy Sauce - Provides tweaks for the scheduler and other settings.
• Latest & improved ZSTD patchset.
• Improved BFQ Scheduler.
• BBRv3 tcp_congestion_control.
• v4l2loopback modules included by default.
• Cherry picked patches from Clear Linux.
• Backported patches from linux-next.
• OpenRGB and ACS Override support.
• NTSync patched and integrated into the kernel.

⬇️ Installation Instructions

Crucial Step: Make absolutely sure your CPU supports the x86_64-v4 instruction set before proceeding.

Run this command in your terminal:

/lib64/ld-linux-x86-64.so.2 --help | grep "x86-64-v4 (supported, searched)"

If this command returns nothing, DO NOT install these kernels.

Next, enable the COPR repository hosting the kernels:

sudo dnf copr enable gharib/kernel-cachyos-v4

Now you can install the kernels:

Default Kernel (BORE)

sudo dnf install kernel-cachyos-v4 kernel-cachyos-v4-devel-matched 
# or for LLVM-ThinLTO
sudo dnf install kernel-cachyos-v4-lto kernel-cachyos-v4-devel-matched

LTS Kernel

sudo dnf install kernel-cachyos-lts-v4 kernel-cachyos-lts-v4-devel-matched
# or for LLVM-ThinLTO
sudo dnf install kernel-cachyos-lts-v4-lto kernel-cachyos-lts-v4-devel-matched

Real-time Kernel

sudo dnf install kernel-cachyos-rt-v4 kernel-cachyos-rt-v4-devel-matched
# or for LLVM-ThinLTO
sudo dnf install kernel-cachyos-rt-v4-lto kernel-cachyos-rt-v4-devel-matched

🚨 Lastly, if you use SELinux, you need to enable the necessary policy to be able to load kernel modules:

sudo setsebool -P domain_kernel_load_modules on

Fedora Silverblue

cd /etc/yum.repos.d/
sudo wget [https://copr.fedorainfracloud.org/coprs/gharib/kernel-cachyos-v4/repo/fedora-$](https://copr.fedorainfracloud.org/coprs/gharib/kernel-cachyos-v4/repo/fedora-$)(rpm -E %fedora)/gharib-kernel-cachyos-v4-fedora-$(rpm -E %fedora).repo
sudo rpm-ostree override remove kernel kernel-core kernel-modules kernel-modules-core kernel-modules-extra --install kernel-cachyos-v4
sudo systemctl reboot

Default Kernel Setup

By default, Fedora will use the kernel that was most recently updated by dnf, which will lead to inconsistent behavior if you have multiple kernels installed. We can tell Fedora to always boot with the latest CachyOS kernel by running a script after kernel updates.

Create a file in /etc/kernel/postinst.d:

sudo nano /etc/kernel/postinst.d/99-default

Enter the following content:

#!/bin/sh

set -e

grubby --set-default=/boot/$(ls /boot | grep vmlinuz.*cachy | sort -V | tail -1)

Make root the owner and make the script executable:

sudo chown root:root /etc/kernel/postinst.d/99-default ; sudo chmod u+rx /etc/kernel/postinst.d/99-default

The next time any installed kernel gets an update, the system will change the default kernel back to the latest CachyOS kernel. This way you can keep the official Fedora kernel as a fallback backup.

🧩 Addons

We provide a few addons that supplement the kernel packages and system.

• CachyOS-Settings - Settings used in CachyOS (includes modprobe config, udev rules, etc) packaged for Fedora.
• scx-scheds - sched-ext schedulers. Provides both scx-scheds releases and scx-scheds-git package.
• scx-manager - Simple GUI for managing sched-ext schedulers via scx_loader.
• ananicy-cpp & cachyos-ananicy-rules - Auto nice daemon with rules support.

⬇️ Installation instructions

(Note: If you are strictly pulling addons from the upstream project, use the bieszczaders repo below. Otherwise, replace with your own addon COPR if you fork them).

sudo dnf copr enable bieszczaders/kernel-cachyos-addons

CachyOS-Settings

sudo dnf swap zram-generator-defaults cachyos-settings
sudo dracut -f

scx-scheds and scx-tools

sudo dnf install scx-scheds scx-tools

or -git packages

sudo dnf install scx-scheds-git scx-tools-git

For Fedora Silverblue / Kinoite:

sudo rpm-ostree install scx-scheds scx-tools
sudo systemctl reboot

You can use scxctl to start/change the scheduler with profiles/custom flags.

📖 Usage guide available in the CachyOS wiki.

scx-manager

sudo dnf install scx-manager

ananicy-cpp

After further development of the sched-ext schedulers, ananicy-cpp is usually okay to be used alongside them. However, if you experience any stalls or instability, consider disabling it as a troubleshooting step.

sudo dnf install ananicy-cpp
sudo systemctl enable --now ananicy-cpp

Thanks

Special Thanks to @andersrh, @TrixieUA and CachyOS Team for providing anything in this repository. Actually I have made some little changes to the spec files and compiled them!