The Linux kernel 7.4 is still a way out, with a late October/early November release anticipated, but it's already showing promising and usability updates for Linux PCs all around. A new patch called PerfOpt (Performance Optimization) is now slated to be merged into kernel 7.4, promising even more performance upgrades for AMD iGPUs.
Per the recent Linux kernel mailing list, PerfOpt "allows privileged integrated I/O devices (GPUs) to bypass the IOMMU when directly accessing system memory. The IOMMU only enforces the IR/IW permission bits without GPA->SPA translations." Effectively, the patch reduces the amount of system overhead for the iGPU, which should result in a performance boost for basically any application that's sensitive to latency or throughput.
According to testing by Phoronix, local LLM performance on an AMD Strix Halo APU can be improved by as much as 18-23%. PerfOpt should be relevant to basically everyone on an AMD iGPU, but it may be especially important for those on low-power devices, like the Valve Steam Deck and other AMD-powered handhelds, since they are already starved for GPU performance. There's no telling when Valve will update its Steam OS kernel to Linux 7.4, but distributions like Cachy OS, which prioritize performance and fast updates, will likely see the patch sooner.
Source: TechPowerUp News · Summarized by HeadlinesBriefing