Unreal Engine 5.5.4 Cyberpunk Tech Demo Pushes RTX 4090 to Its Limits With Lumen and Ray Tracing Enhancements

A visually impressive Unreal Engine 5.5.4 tech demo inspired by Blade Runner and classic Cyberpunk aesthetics is now available, showcasing the capabilities—and performance demands—of Lumen Global Illumination, advanced reflections, and hardware ray tracing.

Created by Pasquale Scionti, the scene was originally developed in Unreal Engine 5.3 using only dynamic lighting, without Lumen, path tracing, or ray tracing. The latest version dramatically enhances the environment using Lumen Global Illumination and Reflections, along with hardware-accelerated ray tracing for Ambient Occlusion, Reflections, and Shadows.

While the visuals are undeniably striking, they come at a steep performance cost. Even on NVIDIA’s flagship RTX 4090, the scene struggles to maintain 60 FPS at 1440p, demonstrating just how demanding real-time lighting and reflection systems have become.

Unreal Engine 5.5 is the latest major release from Epic Games and has already been leveraged for fan remakes and tech experiments, such as unofficial remasters of Zelda: Ocarina of Time and Skyrim. However, performance remains a consistent challenge. According to Bryan Heemskerk of Massive Damage, when UE5 first launched, GPUs were "two generations behind." As a result, it's expected that more fluid experiences won’t be possible until the arrival of next-gen hardware like the RTX 6000 series.

This Cyberpunk demo is a striking example of both the promise and the growing pains of real-time rendering tech. While cinematic lighting and photorealistic reflections are within reach, fully enjoying them still requires some of the most powerful hardware available—and even then, with compromises.

Do you think performance trade-offs are worth it for visuals like these—or would you rather have smooth gameplay over ultra-realistic lighting?