Optimized Repositories

Our aim to deliver a performance-optimized distribution necessitates recompiling essential Arch Linux packages for x86-64-v3, x86-64-v4 and Zen4 architectures.

• x86-64-v3: 5%-20% performance uplift compared to x86-64.
• x86-64-v4: Delivers substantial performance gains through AVX512 support, depending on the workload.
• Zen 4/5: In addition to the x86-64-v4 instruction set, the following are added:

abm, adx, aes, avx512bf16, avx512bitalg, avx512ifma, avx512vbmi, avx512vbmi2, avx512vnni,
avx512vpopctndq, clflushopt, clwb, clzero, fsgsbase, gfni, mwaitx, pclmul, pku, prfchw,
rpdid, rdrnd, rdseed, sha, sse4a, vaes, vockmulqdq, wbnoinvd, savec, xsaveopt, xsaves

Customized Packages

Our CachyOS-PKGBUILDs repository contains packages that receive ongoing updates, patches and backported fixes. To boost performance, we selectively implement PGO, LTO, and BOLT optimizations depending on the need. We also maintain a couple of -git packages e.g mesa-git.

Adding Our Repositories to an Existing Arch Linux Install

Caution

Installing the CachyOS Pacman will install a forked pacman with features added from CachyOS, like “INSTALLED_FROM” and an automatic architecture check. Pacman 6.1 added a feature validation feature, which could lead when using the Arch Linux pacman into warnings. We are working with Arch Linux to provide a proper compatibility again. If you want to avoid this, don’t add the “cachyos” repository, which contains the customized pacman. All other repositories like cachyos-v3, cachyos-v4, cachyos-extra/core-v3/4 are fine to add.

Tip

Before considering adding our repositories. Please take a look to the CPU compatibility list

Automated

We provide a script that automates the installation of our repositories to your existing Arch-based installs.

curl https://mirror.cachyos.org/cachyos-repo.tar.xz -o cachyos-repo.tar.xz
tar xvf cachyos-repo.tar.xz && cd cachyos-repo
sudo ./cachyos-repo.sh

How the script works

This script will detect the instruction sets your CPU is capable of and install whichever version of our repositories that are the most optimized for it. It also backs up your old pacman.conf for repository removal via the script.

Manual

1. Install CachyOS keyring:

   # Import the repository key
   sudo pacman-key --recv-keys F3B607488DB35A47 --keyserver keyserver.ubuntu.com
   # Sign the repository key
   sudo pacman-key --lsign-key F3B607488DB35A47

2. Install the necessary packages:

   sudo pacman -U 'https://mirror.cachyos.org/repo/x86_64/cachyos/cachyos-keyring-20240331-1-any.pkg.tar.zst' \
   'https://mirror.cachyos.org/repo/x86_64/cachyos/cachyos-mirrorlist-18-1-any.pkg.tar.zst' \
   'https://mirror.cachyos.org/repo/x86_64/cachyos/cachyos-v3-mirrorlist-18-1-any.pkg.tar.zst' \
   'https://mirror.cachyos.org/repo/x86_64/cachyos/cachyos-v4-mirrorlist-6-1-any.pkg.tar.zst' \
   'https://mirror.cachyos.org/repo/x86_64/cachyos/pacman-7.0.0.r6.gc685ae6-3-x86_64.pkg.tar.zst'

3. Add the CachyOS repositories to the pacman config:

   Note

   These repositories should be put above Arch Linux Repositories.

   /etc/pacman.conf

   # If your CPU supports x86-64, then add only [cachyos] repositories
   # cachyos repos
   [cachyos]
   Include = /etc/pacman.d/cachyos-mirrorlist
   
   # if your CPU supports x86-64-v3, then add [cachyos-v3],[cachyos-core-v3],[cachyos-extra-v3] and [cachyos]
   # cachyos repos
   # Only add if your CPU does v3 architecture
   [cachyos-v3]
   Include = /etc/pacman.d/cachyos-v3-mirrorlist
   [cachyos-core-v3]
   Include = /etc/pacman.d/cachyos-v3-mirrorlist
   [cachyos-extra-v3]
   Include = /etc/pacman.d/cachyos-v3-mirrorlist
   [cachyos]
   Include = /etc/pacman.d/cachyos-mirrorlist
   
   # if your CPU supports x86-64-v4, then add [cachyos-v4], [cachyos-core-v4], [cachyos-extra-v4] and [cachyos]
   # cachyos repos
   # Only add if your CPU does support x86-64-v4 architecture
   [cachyos-v4]
   Include = /etc/pacman.d/cachyos-v4-mirrorlist
   [cachyos-core-v4]
   Include = /etc/pacman.d/cachyos-v4-mirrorlist
   [cachyos-extra-v4]
   Include = /etc/pacman.d/cachyos-v4-mirrorlist
   [cachyos]
   Include = /etc/pacman.d/cachyos-mirrorlist

4. Finally, update your system with CachyOS packages:

   sudo pacman -Syu

Uninstalling CachyOS Repositories

Automated

Run the following commands to remove the CachyOS repositories from your system:

curl https://mirror.cachyos.org/cachyos-repo.tar.xz -o cachyos-repo.tar.xz
tar xvf cachyos-repo.tar.xz
cd cachyos-repo
sudo ./cachyos-repo.sh --remove

Manual

1. Reinstall the original pacman from Arch Linux:

   sudo pacman -S core/pacman

2. Execute the following command:

   # This avoids getting %INSTALLED_DB% warnings
   sudo find /var/lib/pacman/local/ -type f -name "desc" -exec sed -i '/^%INSTALLED_DB%$/,+2d' {} \;

3. Create a backup of the pacman config file:

   sudo mv /etc/pacman.conf.bak /etc/pacman.conf

4. Switch back to the default Arch Linux packages with the following commands:

   pacman -Qqn | sudo pacman -S -
   sudo pacman -Syu

Tests and benchmarks

Michael from Phoronix has already benchmarked CachyOS a couple of times, which is shown mostly leading in the benchmark graphs and on the Geometric Mean of All Test Results. Since the first benchmark made back in 2022. CachyOS has evolved and matured a lot more in terms of usability and performance.

If you would like to know more about the performance uplift from our repositories. Please check the links below.

• 14/03/2021: In a RFC discussion about the impact of x86-64-v3 was started by Mateusz Jończyk from Arch Linux showed some initial results.

  • RFC: Use x86_64-v2 architecture

• 09/12/2022: First benchmark done by Michael.

  • The Performance Of Arch Linux Powered CachyOS

• 29/02/2024: Phoronix conducted another benchmark demonstrating the difference between x86-64-v4, x86-64-v3 and x86-64 (generic) Packages. Looking at the examples like PHP or GCC, where we customize our PKGBUILDs there is a noticeable performance improvement.

  • Arch Linux CachyOS Benchmarks Of x86-64-v3 & x86-64-v4 Repositories

• 20/08/2024: Michael posted a new benchmark for the AMD Ryzen 9950x on which it includes CachyOS and some others Linux Distributions.

  • Intel Continues To Show AMD The Importance Of Software Optimizations: 16% More Ryzen 9 9950X Performance

  Note

  Liquid-DSP and RocksDB were compiled using the Phoronix Benchmark Suite, ignoring the compilation flags specified in /etc/makepkg.conf resulting in a unexpected performance result for CachyOS.

Learn more

• Instruction sets for the various x86-64 micro-architectures