Unreal Engine 5 Zorah Tech Demo in NvRTX Branch Pushes RTX 5090 to Its Limits, Drops to 13 FPS at Native 4K

In an astonishing showcase of next-gen visual fidelity and raw computational demand, the Unreal Engine 5 Zorah tech demo running on the NvRTX branch has proven too powerful even for NVIDIA’s RTX 5090, the most advanced consumer GPU currently available. In a new test video published by Compusemble, the demo dips as low as 13 FPS at native 4K resolution, underscoring just how far bleeding-edge RTX technology has come—and how far gaming hardware still has to go.

The Zorah demo leverages several of NVIDIA’s most resource-intensive RTX features, including Mega Geometry, ReSTiR Global Illumination, Path Tracing, and RTX Neural Rendering. These technologies, though still experimental in some capacities, provide a glimpse into what the future of real-time rendering could look like. However, the price for such high-fidelity rendering is steep, with native 4K resolution causing massive frame rate drops, even on hardware designed to be a generational leap ahead.

Performance improves with NVIDIA DLSS enabled, but only in Performance Mode can the RTX 5090 sustain framerates above 30 FPS in the heaviest scenes. While this is a reminder of the benefits of intelligent upscaling technologies, it also highlights the performance ceiling of current-gen consumer GPUs when confronted with fully ray-traced, photorealistic workloads.

In addition to the eye-catching rendering, the demo implements RTX Neural Rendering, a technology that compresses and reconstructs thousands of textures through neural network inference. This technique not only saves VRAM and system RAM significantly more than traditional texture compression, but also opens the door for more expansive environments without sacrificing memory efficiency. Developers can find more on this emerging technology via NVIDIA’s official blog.

Although this level of rendering is still years away from real-time gaming adoption, the Zorah demo offers a breathtaking look at the upper limits of interactive graphics, reaffirming Unreal Engine 5’s position as the most forward-looking engine in modern development—and signaling what might be possible as GPUs continue to evolve.

Would you sacrifice ultra-high settings for stable performance, or are you willing to chase visual perfection at the cost of FPS? Let us know in the comments!