Valve has put an experimental VIDEO CODEC called PYROWAVE into the September 21 Steam Client BETA. The pitch is HIGH BANDWIDTH, LOW LATENCY Remote Play — and the trade-off is NETWORK COST: five to TEN times the bandwidth of Steam’s current streaming codecs, with Gigabit ETHERNET recommended between host and client.
Mixed-News (Chris Steven, Sep 22) walked the BETA notes and the OPEN-SOURCE design. Pyrowave is not Valve’s own code — it is an INTRA-ONLY codec from Hans-Kristian ARNTZEN, the graphics programmer behind VKD3D-Proton, implemented in Vulkan compute shaders and aimed at encode and decode under about 0.1 ms at 1080p and under 0.2 ms at 4K.
Gigabit First. Manual Bitrate Optional.
Valve’s Remote Play post (slouken) is blunt: CONNECT machines DIRECTLY to the router with at least Gigabit ethernet. Steam normally tunes for visual quality with a constant frame size; a quality slider moves bandwidth up and down. Turning AUTOMATIC bitrate off unlocks a MANUAL range from 100 Mbit/s to 500 Mbit/s.
HDR switches on AUTOMATICALLY when host and client both support it. YUV 4:4:4 — more colour precision — stays OFF by default because it costs extra BANDWIDTH and processing; Valve suggests enabling it for desktop streaming or reading text on a 4K display.
Windows and macOS Now. Linux Needs SteamRT3.
Pyrowave is LIVE in Steam beta on Windows and macOS. On Linux and SteamOS it needs the experimental SteamRT3 client in System Settings. Steam Link MOBILE support is listed as COMING SOON. Valve build callouts in the Remote Play thread point at Steam Version 1790036264 (client build dated Sep 21, 2026).
That VR caveat matters this week. Mixed-News notes Valve’s post says nothing about VR: Remote Play here streams FLAT PC games to another PC, a Steam Deck, a TV, or a phone. Steam Machine still CANNOT stream VR titles to Steam FRAME. Pyrowave is a LATENCY bet for wired LOCAL STREAMING, not a Frame wireless fix.
Valve is not promising a win for every setup. Total LATENCY is still encode plus NETWORK plus decode plus display. The Remote Play performance graph is the tool Valve points testers at. “Your particular setup may or may not benefit from the new codec,” the post says — try it on a wired Gigabit path and report back.
Sources: Valve Steam Remote Play — Pyrowave video codec now in beta (slouken, Sep 21, 2026); Mixed-News — Steam’s new Pyrowave codec (Chris Steven, Sep 22, 2026); Linuxiac — Steam tests Pyrowave on Linux and SteamOS (Sep 22, 2026); Hans-Kristian Arntzen — PyroWave codec design notes.