By Nick Evanson
AMD introduced machine learning improvements to its upscaling and frame generation with RDNA 4 and FSR 4. Even buyers of a new RX 9070 initially depended on developers adding FSR 4 support to their games. AMD's latest FidelityFX SDK now appears to offer another route: using DLSS Swapper and renaming a single file.
The developer behind DLSS Swapper shared a report from a visitor to the app's GitHub who said they had replaced a game's FSR 3 files to enable FSR 4. DLSS Swapper replaces DLL (dynamic linked library) files in game folders, allowing users to try different versions of DLSS, FSR, and XeSS.
How to import the new DLL
DLSS Swapper creator beerdamore provided the following instructions:
- Install DLSS Swapper after downloading it.
- Download the latest FidelityFX SDK from AMD.
- Unpack the archive into a new folder.
- Open the Kits\FidelityFX\signedbin\ folder.
- Change the filename amd_fidelityfx_upscaler_dx12.dll to amd_fidelityfx_dx12.dll.
- Launch DLSS Swapper, click the Library icon, and choose FSR 3.1 DirectX 12 at the top.
- Click Import in the top corner.
- Browse to the folder containing the renamed amd_fidelityfx_dx12.dll and import that file.
- Check the FSR options list for v4.0.2.44888.
That version may appear in parentheses. Without a Radeon RX 9000-series graphics card, FSR 3.1.5 is likely to be the newest version your GPU supports.
Next, choose the game that should receive the DLL. In its FSR options, click the version number and select 4.0.2 from the long menu. After the DLL swap, the game should, in theory, launch with FSR 4 listed among its upscaling options.
What remains unverified
Evanson cautions that he is unsure whether the game actually uses FSR 4 or merely displays the DLL version. The procedure cannot make an incompatible GPU run FSR 4, and verification so far covers only a handful of FSR 3.1 games.
DLL swapping is straightforward and, according to the article, safe as long as the files come directly from AMD, Nvidia, or the relevant supplier. If the game does not use FSR 4, or you dislike the resulting upscaling, you can restore the previous DLL.
If the method works as hoped, RDNA 4 owners could gain access to FSR 4 beyond the games that already support it officially. At the time of writing, Evanson said the publication planned further investigation using RX 9000 cards and several FSR 3.1 games.
About Nick Evanson
Nick's interest in computers and gaming began in the early 1980s. After university, he taught physics and IT before starting to write about technology in the late 1990s. He worked with MadOnion on help files for 3DMark and PCMark, then briefly worked at Beyond3D.com. He later joined Futuremark, the renamed MadOnion, as editor-in-chief of its PC gaming site, YouGamers.
Following YouGamers' closure, Nick spent years lecturing in engineering and computing before returning to writing, including four years covering PCs and technology at TechSpot.com. GPUs and open-world RPGs remain particular interests.
