Tuesday, February 24th 2026
OptiScaler One-Ups AMD With FSR 4 Vulkan Support
We previously covered how enterprising gamers managed to bypass AMD's FSR 4 restrictions to get Redstone frame generation tech working on older RDNA GPUs with OptiScaler. Now, it seems as though OptiScaler has managed bypass another one of AMD's limitations that restricted FSR 4 implementations to DirectX 12 games. According to the build notes uncovered by a Reddit user u/eduhfx, OptiScaler is testing adding Vulkan support in a new test build v0.9.0-pre10. Notably, OptiScaler is using a compatibility tool to work around FSR 4's lack of Vulkan support, similarly to how Linux translates DirectX, calls to Vulkan with DXVK or VKD3D. This also means that FSR 4 on Vulkan should work on Linux systems, as well, where games often run better under Vulkan than DX12—although at the time of writing, FSR 4 w/DX12 currently has issues running on Linux due to a Mesa issue that seemingly cannot be solved by the OptiScaler team.
Sources:
u/eduhfx on Reddit, OptiScaler on GitHub
Added Vulkan w/DX12 support - FSR 4 VK w/DX12, FSR 2.1 VK w/DX12
Currently, known issues:
FSR 4 VK w/DX12 has issues on Linux due to missing Mesa extensions
Not interested in reports as nothing we can fix on our side as far as we know
21 Comments on OptiScaler One-Ups AMD With FSR 4 Vulkan Support
I did a quick and dirty test on three different systems last night using Baldur's Gate 3 running in Vulkan with DLSS inputs and FSR4 outputs.
On my main system (RX 9070 XT), FSR4 seems to work pretty much perfectly.
On my old system (RX 6800 XT), with FSR4 INT8, it also seems to work perfectly.
Out of morbid curiosity, I tested it on my SFF system (Arc Pro B50), with FSR4 INT8 you get significant display corruption and it's pretty much unusable. Interestingly, DX11 with FSR4 INT8 was visually fine, though with significantly worse performance than XeSS (4K, Ultra Preset, Performance DLSS Input: low 30s on FSR4 INT8 vs high 40s XeSS).
I might do a more scientific test after work.
Yet it's looking more likely at this point they'll send in a mean cease and desist letter to the developers of this app and have them remove any and all references to "stolen" proprietary source code and cease trying to make this work on unauthorized configurations
videocardz.com/newz/amd-suggests-it-may-open-source-fsr-4-after-all-following-accidental-release-last-year
Although I wouldn't be surprised if it was an intentional leak by an engineer fed up with the execs not wanting to release it
RDNA2 also requires swapping some DLLs from 23.9.1 (which is mysteriously absent from AMD's website, wonder why that is) to the latest driver or you'll get horrible ghosting artifacts.
If you want to use INT8 FSR you have to acquire the leaked dll yourself and manually replace the file.
I think AMD should just hire the Optiscaler guy to make these features official, but who knows if they can afford to do it, given they're spending money they don't have on an AI bubble that could pop.
(We know you won’t)
If you can build an INT8 version from the 4.0.3 source that has been published on GPUOpen instead of relying on the prerelease leak, then this is pretty much a moot point anyways. I wouldn't know, frankly I find the whole situation parts of amusing, parts of boring, and a whole heap of sad. I'll stick to my much more powerful, far more polished and most importantly, drama-free Nvidia hardware for the time being.
We caught wind of Intel advertising for people with knowledge of developing games for Linux, albeit it's likely less the company bolstering its existing teams and more it's trying to recover from the 2025 layoffs. Now, Nvidia is also posting job adverts to get people interested in developing for gaming on Linux.
www.xda-developers.com/nvidia-is-also-hunting-for-linux-developers-to-help-advance-gaming-on-foss/
AMD wont bother wasting it's time and resources. Also hilarious to call it stolen when they're the ones who initially published it.Doom: The Dark Ages and the Indiana Jones game. Also Baldurs Gate 3 and No Man's Sky come to mind.