# OptiScaler Guide: How to Enable AMD FSR 4 in Vulkan Games

> Learn how to force AMD FSR 4 in Vulkan games using OptiScaler. A step-by-step guide to bypassing RDNA 4 limits for better upscaling quality.

- Canonical URL: https://coreiten.com/en/article/optiscaler-guide-how-to-enable-amd-fsr-4-in-vulkan-games
- Language: en
- Section: Pc & Hardware
- Author: Sami
- Published: 2026-03-01T02:08:00+03:00
- Modified: 2026-03-01T02:08:00+03:00
- Publisher: CoreITen (https://coreiten.com)
- Keywords: OptiScaler, AMD FSR 4, Vulkan games, FSR 4 Vulkan support, Doom Eternal FSR 4

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PC gamers can now bypass AMD’s official limitations by using **OptiScaler** to force FSR 4 upscaling into Vulkan-based titles, a feat previously described by the manufacturer as architecturally impossible. While AMD officially restricts its latest machine learning-based upscaling technology to RDNA 4 GPUs and DirectX 12 environments, the open-source community has developed a sophisticated workaround. This tool creates a background DirectX 12 device that intercepts critical datasuch as color buffers, depth buffers, and motion vectorsfrom the Vulkan game, processes the FSR 4 inference, and seamlessly returns the upscaled image.

This breakthrough is particularly significant for enthusiasts seeking superior image quality. The bridge replaces older FSR 3.1 implementations with advanced FSR 4 libraries, resulting in cleaner image reconstruction, significantly reduced ghosting, and more stable edges. Early tests indicate that even the Performance mode of FSR 4 often delivers better detail restoration than the Quality preset of FSR 3.1. The community compatibility list currently supports **525 games**, including major Vulkan titles like *Doom Eternal*, *No Man's Sky*, and the upcoming *Indiana Jones and the Great Circle*.

### Step-by-Step Installation Guide

To integrate this technology into your supported games, follow this precise procedure derived from the latest OptiScaler release (version 0.9.0-pre10):

- **Download the Tool:** Acquire the latest pre-release version (e.g., 0.9.0-pre10) from the official OptiScaler GitHub repository.
- **Initialize the Config:** Extract the files and run `Launch.bat`. When prompted in the command window, press **7**, then **1**, then **1** to configure the environment.
- **Patching (id Tech Specific):** For games running on the id Tech engine, such as *Doom Eternal*, you must use the **OptiPatcher** tool (included or linked in the description) on the game's executable file once to enable injection.
- **In-Game Activation:** Launch your game normally. Open the OptiScaler settings menu overlay, select the new **FSR 3 option** (which acts as a bridge to FSR 4), and choose your desired preset (Quality, Balanced, or Performance).

### Hardware and OS Considerations

While this tool unlocks FSR 4 for a broader range of hardware, users on older architectures like RDNA 2 (RX 6000 series) should expect an experimental experience with approximately 20-30% performance overhead. If instability occurs, dropping the preset to 'Balanced' is recommended. Additionally, Windows 10 users may need to install the **FsrAgilitySDKUpgrade** to ensure compatibility, while Linux users can leverage DLSS inputs for effective operation. The tool also supports swapping other upscalers like DLSS and XeSS, providing a versatile solution for modern PC gaming.

### My Take

The release of this OptiScaler update is a testament to the ingenuity of the PC modding community. It challenges the narrative that certain software features are strictly bound to specific hardware generations. By successfully bridging Vulkan data to a DX12 container for FSR 4 inference, the developers have proven that "architectural impossibility" is often a matter of resource allocation rather than physical limitation. For gamers with RDNA 3 cards who felt left behind by the RDNA 4 exclusivity, this is a vital tool that extends the lifespan and visual fidelity of their existing hardware.

## Sources

- [wccftech.com](https://wccftech.com/how-to/how-to-add-amd-fsr-4-upscaling-to-any-vulkan-game-using-optiscaler/)