Last week I ran benchmarks of the new AMD PerfOpt feature being introduced in Linux 7.4. In those PerfOpt benchmarks on current-gen AMD Ryzen AI APUs/SoCs the AI performance improved as much as 18~23%. Several Phoronix readers expressed interest in seeing how prior-gen AMD Ryzen hardware benefited or not from PerfOpt, so here are some additional benchmarks.

This AMD IOMMU Performance Optimization feature AMD integrated graphics can bypass the IOMMU when directly accessing system memory to avoid the associated overhead. With Linux 7.4 this PerfOpt feature will be enabled by default when using Radeon integrated graphics.

For those curious how AMD PerfOpt works for prior-gen hardware, I pulled out an older Lenovo ThinkPad P14s Gen 4 laptop with the AMD Ryzen 7 PRO 7840U with Radeon 780M integrated graphics. The Radeon 780M is still fairly common and this Zen 4 laptop SoCs still fairly robust in 2026. As to be shown in these benchmarks, with PerfOpt there now is added performance potential for those still using this class of hardware.

The benchmarks on this ThinkPad P14s G4 were done on Ubuntu 26.04 LTS while using a kernel build of the IOMMU next Git tree ahead of the Linux 7.4 merge window opening later this month. No other changes were made to the system during testing beyond toggling the PerfOpt functionality.