Intel Arc B580 tested with SteamOS 3.9, direct boot works but XMX does not
© ETA Prime Intel Arc B580 can now run Valve’s SteamOS without the installation workaround previously required for Intel’s discrete GPU. ETA Prime tested the Battlemage card using the SteamOS Main branch version 3.9 , and was able to boot directly into the operating system with the B580 installed.
The SteamOS 3.9 build shown in the test comes from Valve’s Main development branch rather than the current public Beta channel. Valve continues to expand Intel hardware support, with 3.8.25 adding initial gamepad support for the Intel-powered MSI Claw 8 EX AI+. This is the same branch that ETA Prime used to test AMD Strix Halo a couple weeks back.
In June, SteamOS already recognized the Arc B580, but installing it required an AMD Radeon card. The user had to install an older SteamOS image, update the system and then replace the Radeon card with the Arc B580. The new test skips that process and boots directly with Intel graphics installed. That is no longer required, which means a lot easier use for Intel users.
© ETA Prime Arc B580 tested at 1440p
ETA Prime paired the 12GB Arc B580 with a Core Ultra 5 250K Plus processor. Cyberpunk 2077 reached the mid-70 FPS range at 1440p High using XeSS Quality. The same configuration reportedly achieves roughly 75 to 90 FPS under Windows depending on the scene. Horizon Zero Dawn Remastered ran in the mid-60 FPS range at 1440p High with XeSS Balanced, compared with the mid-70s on Windows.
Fallout 4 and Elden Ring both ran at 60 FPS at 1440p, with Elden Ring using maximum settings without upscaling. Forza Horizon 6 averaged around 74 FPS at 1440p High without scaling, while the Windows result was reported in the mid-80 FPS range. The tester also observed occasional dips, although performance remained above 60 FPS.
© ETA Prime 
© ETA Prime XeSS still lacks XMX acceleration under Linux
The Arc B580 has dedicated XMX engines, but the current open-source Linux driver path does not expose them for XeSS acceleration. XeSS can still run through its shader-based fallback path, but the difference becomes more visible when using lower-quality scaling modes. In other words, the image quality when XeSS is used will simply be higher in Windows.
XeSS Frame Generation and Multi-Frame Generation are also unavailable in this setup. Intel’s current XeSS Frame Generation documentation lists Windows 10/11 and DirectX 12 as requirements. FSR Frame Generation remains an option under SteamOS. Direct boot support therefore removes one of the biggest barriers for Arc B580 systems, but feature support still trails Intel’s Windows driver.
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