# Linux 7.4 to enable Radeon HDMI 2.1 by default, add Apple M4 and Tensor G5 support

> **Key takeaway:** The upcoming Linux 7.4 kernel merge window will bring HDMI 2.1 by default for AMDGPU, initial Apple M4 device trees, Google Tensor G5 mainlining, and AMD PerfOpt IOMMU for improved iGPU AI/LLM performance.

**Published:** 2026-10-18T10:50:00+00:00 
**Source:** Phoronix Benchmarks & Drivers 
**Category:** kernel-os 
**Canonical URL:** https://fosswire.org/news/linux-74-to-enable-radeon-hdmi-21-by-default-add-apple-m4-an.html 

## Summary
Linux 7.4's merge window opens following the 7.3 release, with AMDGPU enabling HDMI 2.1 by default now that VRR and ALLM support is complete. AMD's PerfOpt IOMMU feature will be enabled by default for iGPUs, boosting AI and LLM workloads on prior generations as well as new hardware. The kernel also gains initial Apple M4 and A18 Pro device trees, Qualcomm Snapdragon X2 laptop support, and mainline support for Google's Tensor G5 SoC and Pixel 10 devices.

## Key hardware enablement in Linux 7.4
- **AMDGPU HDMI 2.1**: Enabled by default with VRR and ALLM support, following late-year open-sourcing of related patches
- **AMD PerfOpt IOMMU**: Default-on for iGPUs, specifically targeting AI/LLM performance improvements across generations
- **AMD Zen 6**: BTB CTX isolation, RMPOPT optimization, and P-State driver improvements
- **AMDXDNA**: Adds missing device ID for Ryzen AI Max 400 series (Gorgon Halo) NPU
- **Intel**: BFF driver merged, Battlemage CPU binds and ULLS migration queue improvements, vRAM health checks
- **NVIDIA Nova driver**: Continued development work
- **Qualcomm**: Snapdragon X2 laptop support upstreaming
- **Apple Silicon**: Initial M4 and A18 Pro device trees for MacBook Neo; audio support upstreaming (still not end-user ready)
- **Google**: Tensor G5 SoC and Pixel 10 mainline support
- **File systems**: EXT4 IOmap buffered I/O path, large folios for FUSE
- **Virtualization**: Intel Instruction Timeout (TDX VM DoS mitigation), Microsoft para-virtualized IOMMU Hyper-V driver, steal governor
- **Networking**: Nebula Matrix driver upstreamed
- **Code changes**: Google C Binder driver removed in favor of Rust-based Binder; MM optimizations, faster single-file opens, improved Zstd in-kernel code, AVX-512 xor_gen

## Why it matters
The HDMI 2.1 default enablement finally completes a long-running effort for Radeon users on modern displays. AMD PerfOpt IOMMU could meaningfully improve local AI inference on widely deployed iGPUs. However, Apple M4 support remains developer-only for now, continuing the pattern of slow upstream enablement for Apple Silicon.