The launch of VKD3D-Proton 3.0 just gave Linux gamers and Valve a serious graphics upgrade. The update officially adds support for AMD FSR 4, and under the hood, it may do more than just future-proof Proton. It could give the upcoming Steam Machine a leg up in 4K gaming.

AMD FSR 4 support shows up in VKD3D-Proton 3.0

VKD3D-Proton is a critical part of SteamOS’s DirectX-to-Vulkan compatibility layer, and the 3.0 release is headlined by something big: baked-in support for AMD FSR 4 upscaling. While official use is gated to AMD’s newest RDNA 4 GPUs, code flags suggest INT8 emulation is possible even on older hardware.

That’s no small detail. It means GPUs like RDNA 2 and RDNA 3 the same architecture inside Steam Deck and Valve’s upcoming Steam Machine could tap into FSR 4 with some tweaks.

Unlocking AMD FSR 4 on Steam Deck and Steam Machine

VKD3D-Proton 3.0 doesn’t flip the switch for older GPUs by default, but modders have already proven this workaround works using the leaked FSR 4 INT8 DLLs. The new version of Proton lays the groundwork for making those hacks more seamless within Linux and SteamOS.

Here’s what the update unlocks or enables:

• Native FSR 4 support for RDNA 4 and newer
• Internal flags to emulate FSR 4 on RDNA 2 / RDNA 3
• Linux parity with Windows mods for FSR 4
• Better integration of FSR 4 into Proton workflows

Still, it’s not a silver bullet. The “INT8” emulation path works but at a performance cost. Cleaner visuals come at the expense of frames, something Valve can’t afford to sacrifice if it’s serious about delivering 4K60 on all games.

Steam Machine performance still hinges on GPU

While Valve’s upcoming Steam Machine packs a Zen 4 CPU for headroom, GPU limitations are harder to overcome. Testing on similar setups shows FSR 4 helps, but not without some bottlenecks especially in ray-traced games like Indiana Jones and the Great Circle.

Despite these constraints, Valve may still pull off a proper console rival:

• SteamOS offers more flexibility than Windows
• FSR 4 support, even partial, helps boost fidelity
• Zen 4 CPU gives overhead for demanding titles
• Native upscaling could close the gap with PS5 Pro

FSR 4 could be Valve’s not-so-secret weapon

While PlayStation leans on PSSR for its Pro hardware, Valve’s path may rely on smarter upscaling and flexible software. If AMD delivers official driver-level FSR 4 support, it could be the tipping point for the Steam Machine to truly rival Sony’s offerings.

The tech is nearly there. The clock’s ticking. And with VKD3D-Proton 3.0, Valve just stepped closer to the finish line.