# Linux 7.4 merge window opens with AMDGPU HDMI 2.1 default, AMD PerfOpt, Apple M4 support

> **Key takeaway:** The Linux 7.4 kernel merge window is expected to bring HDMI 2.1 by default for AMDGPU, AMD PerfOpt IOMMU for improved iGPU AI/LLM performance, and initial Device Trees for Apple M4.

**Published:** 2026-10-18T10:50:00+00:00 
**Source:** Phoronix Linux Gaming & Graphics Drivers 
**Category:** open-gaming 
**Canonical URL:** https://fosswire.org/news/linux-74-merge-window-opens-with-amdgpu-hdmi-21-default-amd-.html 

## Summary
With the Linux 7.3 kernel release imminent, the 7.4 merge window is set to open with substantial hardware enablement across AMD, Intel, Apple, Qualcomm and Google. The AMDGPU driver will enable HDMI 2.1 by default now that VRR and ALLM support is in place. AMD's PerfOpt IOMMU feature should improve AI/LLM workloads on integrated graphics including older generations. Intel is preparing for Panther Lake and merging the BFF driver, while Apple M4 and A18 Pro get initial Device Trees though remain non-functional for end users. Qualcomm Snapdragon X2 laptops, Google Tensor G5 and Pixel 10 are also slated for mainline support.

## What's landing in Linux 7.4
- **AMDGPU HDMI 2.1**: Enabled by default with VRR and ALLM support now that previously closed patches have been open-sourced
- **AMD PerfOpt IOMMU**: Default-enabled feature for iGPUs that can yield significant AI/LLM performance gains on current and prior-generation hardware
- **AMD Zen 6**: BTB CTX isolation, RMPOPT optimization, and P-State driver improvements
- **AMDXDNA**: Device ID added for Ryzen AI Max 400 series (Gorgon Halo) NPU
- **Intel**: BFF driver merge, Battlemage CPU binds and ULLS migration queue improvements, vRAM health check with degraded memory handling
- **Apple Silicon**: Initial M4 and A18 Pro Device Trees for MacBook Neo; audio support upstreaming (still not end-user ready)
- **File systems**: EXT4 IOmap buffered I/O path, large folios for FUSE
- **Virtualization**: Intel Instruction Timeout for TDX VM DoS mitigation; Microsoft para-virtualized IOMMU Hyper-V driver; steal governor
- **Code changes**: Google C Binder driver removed in favor of Rust-based Binder; Zstd in-kernel improvements; AVX-512 xor_gen optimization

## Why it matters
The AMDGPU HDMI 2.1 default and AMD PerfOpt IOMMU should directly benefit desktop Linux users with modern Radeon hardware and those running local AI/LLM workloads on AMD iGPUs. However, Apple M4 support remains early-stage and non-functional for end users, continuing the pattern of slow Apple Silicon upstreaming.