The Linux 6.18 kernel, released as the 2025 long-term support version, provides significant performance improvements over Linux 6.12 LTS for fifth-generation AMD EPYC processors. Benchmarks on an AMD EPYC 9755 dual-processor server demonstrate advantages from AMD-specific optimizations and general kernel enhancements. This upgrade is expected to drive adoption in enterprise and hyperscaler environments.
The Linux 6.18 kernel marks this year's long-term support (LTS) release, promising extended maintenance and broad uptake by enterprises and hyperscalers. While Linux 6.12 LTS will receive support at least through the end of 2025, moving to 6.18 LTS offers compelling performance gains, particularly for the current-generation AMD EPYC 9005 "Turin" series based on Zen 5 architecture.
These processors debuted last year with solid initial support in Linux 6.12 LTS. However, subsequent kernel developments have introduced targeted improvements for AMD hardware alongside broader optimizations, leading to measurable benefits in various workloads.
Testing was conducted on an AMD EPYC 9755 dual-processor (2P) server equipped with 24 x 64GB DDR5 memory, a Kioxia PCIe Gen 5 NVMe SSD, and Ubuntu 25.10 as the base operating system. The kernels evaluated included:
- Linux v6.12: The original 2024 LTS baseline.
- Linux v6.12.62: The latest point release incorporating back-ported stable patches.
- Linux v6.18: The new 2025 LTS stable kernel.
- Linux v6.19 (Git state as of December 18): An early preview of the upcoming kernel, expected to stabilize in February 2026.
Dozens of benchmarks were run across these versions, with the CPU frequency scaling governor set to "performance" for consistency. Power consumption for the dual CPUs was also tracked to assess efficiency changes. Results indicate worthwhile uplifts in performance for Linux 6.18 LTS compared to 6.12 LTS, though Linux 6.19 introduces some regressions alongside new features.
This evolution underscores the ongoing refinement of Linux support for high-performance server hardware, benefiting data centers reliant on AMD EPYC systems.
