PHP 8.6 delivers 20% speed gain over 7.4 on Intel Xeon — but 8.5 still edges ahead

Phoronix has published fresh PHP benchmarks comparing performance from version 7.4 through the latest PHP 8.5 stable and the current Git state of PHP 8.6, ahead of its official release later in 2026. The tests were run on an Intel Xeon 678X workstation (HP Z4 G6i) running Fedora 44, using command-line execution to avoid web server overhead.

The widely-used PHPbench benchmark showed a steady climb in performance across the PHP 8.x releases. PHP 8.6 Git delivered roughly a 20% improvement over PHP 7.4. However, the current PHP 8.6 Git build regressed slightly compared to the stable PHP 8.5 release — the Phoronix team expects this gap to be closed by the time PHP 8.6.0 ships later in 2026.

The integrated PHP micro-benchmarks revealed no significant differences between versions. Phoronix's own self-test indicated that PHP 8.5 and newer versions are performing well, though specific JIT performance figures were not detailed in the article.

Notably, the benchmark suite could not include PHP 7.4 and earlier releases because older unsupported versions segfaulted when built with the modern GCC 16 compiler toolchain on Fedora 44. All PHP builds were compiled using the same compiler and toolchain to ensure a fair comparison.

The tests were limited to a handful of command-line PHP benchmarks, focusing on raw execution speed rather than web server throughput. The results suggest that while PHP 8.6 is not yet faster than 8.5, the overall trend of incremental performance gains continues across the 8.x series.