AMD’s latest Radeon RX 9070 and RX 9070 XT graphics cards, powered by the RDNA 4 architecture, are running into major performance issues when ray tracing is enabled in Unreal Engine 4 titles using DirectX 12. According to recent tests by Digital Foundry, as well as complaints from early adopters, the problem causes severe stuttering, making gameplay nearly impossible.

The issue first came to light in early July when players reported frequent freezes and frame drops on Reddit. Digital Foundry has since confirmed the findings in their own benchmarks.

Severe Stuttering in Popular Games

In Hellblade: Senua’s Sacrifice, stutters occurred immediately, with frame rates dropping to 0 fps for several seconds at a time. Similarly, Sackboy: A Big Adventure suffered massive performance hits whenever new visual effects were triggered — something as simple as popping a bubble caused the game to freeze briefly.

The freezes appear to be linked to on-the-fly shader compilation. In Sackboy, the stutters disappeared after an effect had been loaded once, pointing to an issue with the initial shader compilation process.

Digital Foundry’s Alex Battaglia noted that Returnal ran smoothly during his initial tests with ray tracing enabled, but he warned that the game has a very short pre-compilation phase, meaning the bug could still appear later in the campaign.

What’s Causing the Problem?

On RDNA 4-based GPUs, shaders seem to take significantly longer to compile during gameplay compared to other architectures. This unusual delay suggests a possible driver-level issue or even a deeper architectural bottleneck within RDNA 4. Competing GPUs from NVIDIA and Intel do not exhibit this problem.

Digital Foundry confirmed that they are sharing their findings with AMD, urging the company to investigate and release a fix as soon as possible.