Linux kernel compilation times are shrinking. According to Tom's Hardware, Phoronix's Michael Larabel reports that a clean defconfig x86-64 kernel build now takes roughly 15 seconds on his dual-socket AMD EPYC 9575F workstation. That's down from over 22 seconds before applying the latest patches from Linux MM developer Lorenzo Stoakes, who has been working with AI/LLM assistance to remove build bottlenecks.
The test rig is far from typical: two 64-core EPYC 9575F processors (128 cores, 256 threads), 1.5TB of DDR5-6400, and a PCIe Gen5 NVMe SSD, running stock Ubuntu 26.04 LTS. No RAMdisk was used. The same patches also cut an allmodconfig build — which enables thousands of drivers — from 169 seconds to 134 seconds.
Larabel suggests the next milestone is within reach: a sub-10-second defconfig build on AMD's upcoming Zen 6-based EPYC 9686F, with MRDIMMs and PCIe Gen6 storage. Home PCs and laptops, however, will still take longer, so the coffee break isn't completely dead for everyone.
Since this is based on a single source, these figures are as reported by Tom's Hardware and have not been independently verified. The trend is consistent with both hardware core-count increases and software optimizations, though the two factors are hard to separate in this test.