With the recently-launched Ubuntu 25.04 and Fedora 42 Linux distributions I’ve been seeing very healthy competition on Intel and AMD x86_64 hardware between these two leading Linux operating systems. But, surprisingly, after evaluating the AArch64 performance I was surprised to find Ubuntu 25.04 delivering a decisive advantage over Fedora 42 when testing on Ampere Altra using a System76 Thelio Astra workstation.
Given the competitive AMD and Intel performance between last month’s Ubuntu 25.04 and Fedora 42 releases, I assumed it would be much the same way on AArch64. After all, Linux 6.14 is in use by both Linux distributions as is other common versions like OpenJDK Java 21 and Python 3.13.
Fedora 42 though is on the new GCC 15 compiler unlike Ubuntu 25.04 sticking to GCC 14. On the System76 Thelio Astra there is also an important difference that Ubuntu 25.04 defaults to the cppc_cpufreq driver with the ondemand governor while Fedora 42 defaulted to cppc_cpufreq with the Schedutil governor for relying on kernel scheduler utilization data.
Whatever the main culprit(s), Ubuntu 25.04 delivered much better performance than Fedora 42 on the System76 Thelio Astra with Ampere Altra Max 128-core ARMv8 configuration. In case you missed it, a recent article also looked at the strong performance upgrade for Ubuntu 25.04 over Ubuntu 24.04 LTS on the System76 Thelio Astra.
