SCSKiller

Shader Compilation Stutter Killer. SCSKiller compiles your games' shaders into your GPU driver's cache before you play, so the game doesn't stop to compile them mid-game. Free and open source, for Windows.

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> [!WARNING] > The only official downloads are this repository's [Releases](https://github.com/BlueHeisenberg/SCSKiller/releases). > See [official links](#official-links) for the accounts and sites that belong to SCSKiller.

SCSKiller's library: games grouped by store, with shader and pipeline counts, cache size, compile time, a status such as Needs rebuilding or Warmed, and Play buttons.

## Why A game that meets a new effect has the GPU driver compile its shader on the spot, and the frame waits: that's shader compilation stutter. SCSKiller reads the shaders a game ships with, works out the pipelines it will build, and compiles them into the driver's cache ahead of time, in its own process with the game closed. ## Results About 5 minutes of play per game, from a cold driver cache and after compiling with SCSKiller. A stutter is a shader compile the game waited 20 ms or more for.

Game	GPU	Measurement	Cold	With SCSKiller
Final Fantasy VII Rebirth	NVIDIA RTX 5090	Stutters (≥ 20 ms)	19	0
	NVIDIA RTX 5090	Worst stall	76 ms	5 ms
	AMD Ryzen AI Max+ 395 (Strix Halo)	Stutters (≥ 20 ms)	162	0
	AMD Ryzen AI Max+ 395 (Strix Halo)	Worst stall	291 ms	7 ms
Silent Hill: Townfall	NVIDIA RTX 5090	Stutters (≥ 20 ms)	24	0
Silent Hill: Townfall	NVIDIA RTX 5090	Worst stall	347 ms	8 ms
Hogwarts Legacy	NVIDIA RTX 5090	Stutters (≥ 20 ms)	1,014	87
	NVIDIA RTX 5090	Worst stall	2,400 ms	100 ms
	AMD Ryzen AI Max+ 395 (Strix Halo)	Stutters (≥ 20 ms)	27,743	206
	AMD Ryzen AI Max+ 395 (Strix Halo)	Worst stall	2,146 ms	104 ms
Tiny Tina's Wonderlands	NVIDIA RTX 5090	Stutters (≥ 20 ms)	583	0
Tiny Tina's Wonderlands	NVIDIA RTX 5090	Worst stall	315 ms	13 ms
Star Wars Jedi: Survivor	NVIDIA RTX 5090	Stutters (≥ 20 ms)	9,038	11

Measured with SCSKiller's recorder. Your numbers depend on the game, GPU and driver. SCSKiller fixes shader compilation stutter only, not traversal or streaming stutter, and a shader it couldn't find or record can still compile in game. ## Features - **NVIDIA and AMD**, DirectX 12 games, and DirectX 11 games on NVIDIA. - **Finds your games** in Steam, Epic Games, EA app, GOG, Ubisoft Connect, Xbox (PC), Battle.net, PURPLE, HoYoPlay and Gaijin, plus games you add yourself. - **Puts games known to stutter on top**, with the reason, and marks games whose engine prepares its shaders itself. - **Compiles again after a driver update**, which clears the shader cache, on its own if you let it. - **Optional recorder** for games whose pipelines its files don't give: play a few minutes with it on, then compile. It also records alongside a mod that replaces shaders. - **Frame times per session**: with the recorder on, a game's page graphs your last session and marks shader stutters apart from other hitches. They stay on your PC. - **Play button** that starts the game through its store. - **Community shader hash database** for Patreon supporters: other players' recordings, so your games are covered without recording them first. Sharing yours is opt-in, anonymous and hash-only. - **Leaves anti-cheat games alone** beyond reading their files: no launching, no injecting, no recorder. The one exception is opt-in per game and confirmed every time: an offline session without EasyAntiCheat for ELDEN RING and ARMORED CORE VI, at your own risk. ## Install | Requirement | | |---|---| | OS | Windows 10 (version 2004) or 11, 64-bit | | GPU | NVIDIA or AMD | | Games | DirectX 12, DirectX 11 on NVIDIA | Intel GPUs aren't supported yet: I don't have one to test on. If you'd like to sponsor an Intel Arc GPU, get in touch at [contact@scskiller.com](mailto:contact@scskiller.com). Download `SCSKiller-Setup.exe` from [Releases](https://github.com/BlueHeisenberg/SCSKiller/releases/latest) and run it. It installs for your user only, needs no admin rights and updates itself. Or unzip `SCSKiller--Portable.zip` to any folder you can write to and run `SCSKiller.exe`. It updates itself too, and keeps its settings and data in a `data` folder beside the exe. Turn recording off for your games before you delete the folder, so the recorder leaves the game folders. > [!IMPORTANT] > **Releases aren't code-signed yet**, so the first run will probably show SmartScreen's "Windows protected your PC". > Click **More info**, then **Run anyway**. Updates never show it. Signing through the SignPath Foundation is in > progress. To check a download, compare its SHA-256 with the one in the release notes (PowerShell: > `Get-FileHash `). Smart App Control (Windows 11) blocks unsigned apps outright: if it's on, wait for a signed > release. ## How to use it 1. **Open SCSKiller.** It finds your games and the shaders they ship with. 2. **Queue games and press Compile.** "Add all recommended" is a good start. Keep the game closed while it compiles. 3. **Play**, from your store or with the Play button. SCSKiller can be closed. Left open, it checks that the compile reached the cache the game really uses, and with the recorder on, the game's page shows your session's frame times and anything that still compiled. If a game needs a recording, turn on **Record**, play it for a few minutes, then compile it.

The compile queue: one game compiling with pipelines per second, games waiting, one finished. A game's page: the frame times of the last session, with shader compile stutters marked apart from other hitches and loading, and the list of slow frames.

## FAQ **Can I get banned?** SCSKiller only reads the files of games with anti-cheat and never adds its recorder to them. Its anti-cheat check can still miss a game, so you use SCSKiller at your own risk, and its authors are not responsible for bans, crashes or lost data. **Is it safe with anti-cheat games?** SCSKiller never launches them, injects into them or gives them the recorder. It only reads their files. The exception is the offline session for ELDEN RING and ARMORED CORE VI, which run offline without EasyAntiCheat when their exe is started directly. You allow it per game and confirm every launch, at your own risk. Steam must be running (offline mode is fine). SCSKiller adds `d3d12.dll`, `scskiller.ini`, `scskiller.armed` and `steam_appid.txt` to the game's folder and starts the exe itself, and the recorder records only that process. When the game exits, SCSKiller takes those files out again, keeps the recording and the session's frame times, and checks the folder is as it was, at the next logon or start if SCSKiller was closed or the PC crashed. If those files are still there when you start the game online, you could be banned. **What does it write, and where?** Settings and per-game plans go in `%LOCALAPPDATA%\SCSKiller\` (the `data` folder of a portable copy), and the compiled pipelines go in your driver's own shader cache. Game files are never modified. The optional recorder adds `d3d12.dll`, `scskiller.ini` and `scskiller.armed` to the folder of a game you turn it on for, and turning it off removes exactly those files. `scskiller.armed` says the install was checked for anti-cheat, and goes as soon as anything in the install changes. A game records only if that file is there when it starts. Uninstalling SCSKiller removes these files and the recordings from every game folder. **Does it touch my drivers or their settings?** No. It compiles through DirectX, as the game would. **Do I need an account?** No. Everything the app does on your PC is free. Signing in with Patreon adds the supporter features. **My game isn't detected, or something broke.** Open an [issue](https://github.com/BlueHeisenberg/SCSKiller/issues/new/choose) with the bug or game request template. ## Support the project The app is free and stays free. [Patreon](https://www.patreon.com/SCSKiller) pays for the servers behind the community database. Sign in with Patreon in Settings to unlock your tier. | Tier | You get | |---|---| | **Patreon supporter** | The community shader hash database, and beta builds | | **Patreon backer** | All of that, plus alpha builds and priority on game requests | ## Build from source Visual Studio 2022 (C++ desktop workload with CMake) and the .NET 10 SDK: ``` cmake -S proxy -B proxy/build -A x64 cmake --build proxy/build --config Release dotnet build SCSKiller.slnx -c Release ``` `build/publish.ps1` builds the distribution into `dist\`. Design: [ARCHITECTURE.md](ARCHITECTURE.md). Contributing: [CONTRIBUTING.md](CONTRIBUTING.md). Changes: [CHANGELOG.md](CHANGELOG.md). Security issues go through [SECURITY.md](SECURITY.md), never a public issue. ## Official links - GitHub: https://github.com/BlueHeisenberg/SCSKiller - Website: https://scskiller.com - Patreon: https://www.patreon.com/SCSKiller - Discord: https://discord.gg/st7C4yCTcN - X: https://x.com/SCSKiller Anything else claiming to be SCSKiller isn't. Please [report it](https://github.com/BlueHeisenberg/SCSKiller/issues/new/choose). ## Licence GPL-3.0-or-later ([LICENSE](LICENSE)), with an additional permission for Oodle, the Windows App SDK and graphics driver libraries ([LICENSE-EXCEPTION.txt](LICENSE-EXCEPTION.txt)). Third-party components: [THIRD-PARTY-NOTICES.md](THIRD-PARTY-NOTICES.md). Code signing: [CODE_SIGNING_POLICY.md](CODE_SIGNING_POLICY.md). Not affiliated with any GPU maker, engine maker or game publisher. All product names are trademarks of their owners. ### Forks Forks are welcome under the licence. Please give yours its own name, say it's unofficial and based on SCSKiller, and keep the SCSKiller copyright notices. The measurements and screenshots in this README are SCSKiller's own, so please don't present them as a fork's. Official builds come only from this repository's [Releases](https://github.com/BlueHeisenberg/SCSKiller/releases) page. A fork's builds, bugs and anti-cheat behaviour are its author's: SCSKiller keeps its recorder out of anti-cheat games, and can't vouch for a fork that changes that. Improvements are always welcome back here as pull requests. Fixes, games and ideas from forks make SCSKiller better for everyone.