The differences in compilation speed between Fedora 33 Workstation and Ubuntu 20.10

[EverardoLebsack]

I have conducted comparisons between Fedora 33 Workstation and Ubuntu 20.10, both utilizing the same kernel version (5.11-rc3), identical kernel configurations, and gcc version (10.02), along with the same compilation flags on the same machine (ryzen 2700x, 16GB RAM, nvme storage). Surprisingly, Fedora consistently outperforms Ubuntu in terms of code compilation speeds, exhibiting a noteworthy difference of 10% to 25% faster completion times.

For instance, when compiling the kernel, Fedora finishes the task in 126 minutes compared to Ubuntu's 143 minutes (user time). Similarly, in the case of CERN ROOT compilation, Fedora completes the process in 177 minutes while Ubuntu takes 224 minutes (user time).

This significant disparity has piqued my scientific curiosity, leading me to wonder about the underlying reasons behind such a substantial difference in performance between the two distributions on identical hardware.

Therefore, I kindly request your insights and expertise to shed light on the potential factors contributing to this remarkable divergence in compilation times. I am particularly interested in understanding the technical aspects that might explain these findings.

[williamshane]

When comparing Fedora with Ubuntu, there are a number of possible explanations for the noticeable performance gap in code compilation speeds. Some probable reasons for this could be:

1. Optimizing the Compiler: By default, Fedora and Ubuntu utilize different compilers. Ubuntu uses GCC 9.3.1 while Fedora uses GCC 10.02. Compilation times may be reduced with the help of GCC 10.02's new optimizations and enhancements. Furthermore, it's possible that Fedora has more optimizations enabled by default than Ubuntu.

2. Kernel setup: Compilation times may be affected by differences in kernel setup between Fedora and Ubuntu. The default kernel setting of Fedora might be better suited for performance optimization, whereas Ubuntu's might be more concerned with reliability or compatibility.

[EverardoLebsack]

When comparing Fedora with Ubuntu, there are a number of possible explanations for the noticeable performance gap in code compilation speeds. Some probable reasons for this could be: getting over it

1. Optimizing the Compiler: By default, Fedora and Ubuntu utilize different compilers. Ubuntu uses GCC 9.3.1 while Fedora uses GCC 10.02. Compilation times may be reduced with the help of GCC 10.02's new optimizations and enhancements. Furthermore, it's possible that Fedora has more optimizations enabled by default than Ubuntu.

2. Kernel setup: Compilation times may be affected by differences in kernel setup between Fedora and Ubuntu. The default kernel setting of Fedora might be better suited for performance optimization, whereas Ubuntu's might be more concerned with reliability or compatibility.

Thx. I will consider your solution.