ShaderBeam: Unlock CRT Motion Smoothness on Your High-Refresh-Rate Monitor

Reliving the CRT Glow: ShaderBeam Brings Classic Motion Smoothness to Modern Displays

Remember the hypnotizing dance of light across a cathode ray tube (CRT) monitor? That distinct flicker and the illusion of fluid motion, a stark contrast to the static image of modern screens. For those who yearn for that nostalgic visual experience and the unparalleled motion clarity it offered, a new open-source utility named ShaderBeam is emerging from the digital ether. This innovative tool for Windows aims to meticulously recreate the feel of CRT displays on high-refresh-rate monitors, promising a revival of silky-smooth visuals.

The Magic of CRT and the Birth of ShaderBeam

The secret sauce of CRT's perceived smoothness lies in its fundamental operation. Unlike our current displays that hold a full frame static for the entire refresh cycle, CRTs behaved as impulse displays. A focused electron beam would rapidly scan across the screen, illuminating pixels only for a fleeting moment before moving on. This rapid on-off cycle, coupled with the persistence of vision, created an illusion of incredibly smooth motion, minimizing the distracting blur that can plague even the fastest modern panels. ShaderBeam, a project making its debut in public beta v0.1 as of December 28, 2025, endeavors to capture this essence using the power of your GPU. It achieves this by simulating the precise timing of a CRT beam's scan within a shader, effectively breaking down each frame into sub-frames that mimic the CRT's pulsed illumination.

Blur Busters' Vision: Enhanced Motion Without Harsh Flickering

The driving force behind ShaderBeam's technical underpinnings is the work of Blur Busters, a renowned authority on display technologies and motion clarity. They describe this approach as a sophisticated method for reducing motion blur while ingeniously mitigating the harsh flickering often associated with traditional black frame insertion (BFI) techniques. By leveraging multiple sub-frames per content frame, ShaderBeam can adapt its simulation across a spectrum of refresh rates, meaning a 60 FPS game could appear remarkably cleaner on a 120Hz or even a 240Hz display. It’s a clever digital dance that aims to replicate an analog phenomenon, bringing a tangible leap in visual fluidity.

Technical Hurdles and Optimal Configuration

However, achieving this digital ghost of CRTs isn't without its technical nuances. ShaderBeam operates exclusively in full-screen mode and crucially relies on VSync being enabled to function correctly. The timing and scheduling of your graphics card are paramount; any hiccups, such as missed frames, can manifest as an erratic, distracting flicker, disrupting the intended smooth effect. To circumvent these potential issues, the developers suggest a rather unique setup: employing two graphics cards. One would be dedicated solely to running ShaderBeam, ensuring its precise timing remains undisturbed. Furthermore, several display features are recommended to be disabled for optimal performance. This includes HAGS (Hardware-accelerated GPU scheduling), Variable Refresh Rate technologies like G-Sync and FreeSync, and HDR. Multi-monitor setups and other overlay applications can also potentially interfere with the delicate balance ShaderBeam requires.

The Ideal Canvas: High-Refresh OLEDs and SDR Brilliance

For the best possible experience, ShaderBeam truly shines on displays with exceptional brightness and high refresh rates. Blur Busters specifically recommends OLED displays clocked at 240Hz or higher, as their inherent pixel response times and brightness capabilities provide an ideal canvas. If you encounter banding or color inaccuracies, ensuring your display is operating in SDR (sRGB) mode with a standard gamma curve (2.2 or 2.4) is crucial. This adjustment helps maintain the integrity of the simulated CRT signal. For those eager to experiment with this fascinating technology, the ShaderBeam utility can be found on GitHub, offering a gateway to a smoother, more immersive visual future rooted in the past.

Unlocking Smoother Motion: Key Takeaways

• ShaderBeam is an open-source Windows utility simulating CRT display motion on modern high-refresh-rate monitors.
• It leverages GPU shaders to mimic the pulsed illumination of CRT beam scanning, reducing motion blur.
• The method aims for smoother motion than traditional black frame insertion, with less harsh flickering.
• Optimal performance requires full-screen mode, VSync, and potentially a dual-GPU setup.
• Disabling HAGS, VRR, and HDR is recommended, along with using SDR mode on a high-refresh-rate display (240Hz+ OLED recommended).
• The project is available on GitHub.