Streaming Tuner

Level streaming budget, dialed in.
One budget dial — plus full manual control — over Unreal Engine's level‑streaming console variables, trading game‑thread cost against streaming speed.

---

If you want to support me 👉 Buy on Unreal Engine Marketplace / Fab

Overview

Level streaming in Unreal is governed by a scatter of console variables — how many milliseconds per frame the async loader gets, how large component (un)registration batches are, whether a forced GC runs on unload, whether the game thread blocks when a player outruns streaming, and more. Tuning them by hand means digging through docs and editing DefaultEngine.ini by trial and error.

Streaming Tuner puts them behind one Streaming Budget slider and a set of ready‑made profiles, while still exposing every underlying variable for manual control. Changes apply live in the editor and are written to Config/DefaultEngine.ini, so they carry into packaged builds.

Features

• One budget dial — a single 0.0 → 1.0 slider maps five time/granularity CVars from a cheap floor up to the engine defaults. Low favours frame stability, high favours streaming speed.
• Presets — Open World, Linear Levels, Fast Load, and Custom. A preset fills every field; Custom unlocks the full settings block for hand tuning.
• Full per‑CVar control — every variable the plugin touches is its own field with an inline tooltip (booleans as checkboxes, the rest as numbers).
• World Partition & unified budget — includes wp.Runtime.MaxLoadingLevelStreamingCells and s.UseUnifiedTimeBudgetForStreaming (UE 5.6+).
• Server section — dedicated‑server streaming toggles (EnableServerStreaming, EnableServerStreamingOut, HLOD.ForceDisable).
• Profile data assets — save configurations as Streaming Tuner Profile assets (custom icon, colour and Content Browser category) and load them back into the settings.
• Per‑platform overrides — map platforms to profiles and write each into its platform‑specific Config/<Platform>/<Platform>Engine.ini.
• Runtime API — Blueprint Pause Tuner / Resume Tuner, plus an automatic pause during first‑launch shader compilation so shaders precache with the full budget.
• Quality‑of‑life — Reset To Engine Defaults and Clear Plugin Entries From Ini buttons, and toast notifications when settings apply.

Console variables controlled

Console variable	Exposed as	Purpose
s.AsyncLoadingTimeLimit	Budget	Async loader ms/frame on the game thread
s.LevelStreamingActorsUpdateTimeLimit	Budget	ms/frame updating streaming‑level actors
s.LevelStreamingComponentsRegistrationGranularity	Budget	Components registered per batch on stream‑in
s.UnregisterComponentsTimeLimit	Budget	ms/frame unregistering components on stream‑out
s.LevelStreamingComponentsUnregistrationGranularity	Budget	Components unregistered per batch on stream‑out
s.UseUnifiedTimeBudgetForStreaming	Toggle	Share one frame budget between loading and streaming (UE 5.6+)
wp.Runtime.MaxLoadingLevelStreamingCells	Number	Cap on concurrently loading World Partition cells (0 = unlimited)
s.ForceGCAfterLevelStreamedOut	Toggle	Forced GC pass after a level unloads
s.ContinuouslyIncrementalGCWhileLevelsPendingPurge	Toggle	Incremental GC while levels wait to be purged
wp.Runtime.BlockOnSlowStreaming	Toggle	Stall the game thread when the player outruns streaming
wp.Runtime.BlockOnSlowStreamingRatio	Number	Distance ratio at which blocking kicks in (−1 disables)
wp.Runtime.EnableServerStreaming	Server	Stream cells on a dedicated server
wp.Runtime.EnableServerStreamingOut	Server	Also unload unneeded cells on the server
wp.Runtime.HLOD.ForceDisable	Server	Skip HLOD generation/loading (server)

Exact defaults and availability can vary between engine builds; type the s. / wp.Runtime. prefix in the console to confirm what exists in your version.

Requirements

• Unreal Engine 5.8 (targets Win64 / Mac).
• A C++ project (or the ability to compile plugins) — this is a source plugin.

Installation

1. Copy the StreamingTuner folder into your project's Plugins/ directory (create it if needed): YourProject/Plugins/StreamingTuner.
2. Right‑click your .uproject → Generate Visual Studio project files.
3. Open the project and build when prompted (or build from your IDE).
4. Enable it under Edit → Plugins → Optimization → Streaming Tuner if it isn't already.

Usage

Settings

Open Project Settings → Plugins → Streaming Tuner.

• Preset — pick a profile for a one‑click baseline, or Custom to edit everything.
• Streaming Budget — the coarse dial; drives the five time/granularity fields.
• Settings — the raw console variables. Locked while a preset is active, editable in Custom.
• Settings ▸ Server — dedicated‑server streaming toggles.
• Profiles — assign a Streaming Tuner Profile asset and use Load From Profile / Save To Profile.
• Per‑Platform — add rows of { Platform, Profile } and click Write Per‑Platform Configs.
• Reset To Engine Defaults / Clear Plugin Entries From Ini — restore defaults or clean the plugin's entries out of DefaultEngine.ini for a tidy uninstall.

Profiles

Create one via Content Browser → right‑click → Streaming Tuner → Streaming Tuner Profile. Edit its values, then load it into the settings or reference it from a per‑platform row.

Runtime (Blueprint)

Pause Tuner caches the current values and restores engine defaults; Resume Tuner re‑applies them — useful around heavy startup work. The plugin also pauses itself automatically while shaders precache at first launch, resuming a few seconds after the work goes idle.

How it works

Changing a value sets the console variable live (in editor) and writes it to the [ConsoleVariables] section of Config/DefaultEngine.ini, which the engine applies at startup — so tuned values persist into packaged builds. Per‑platform overrides are written to Config/<Platform>/<Platform>Engine.ini, layering only on that platform.

Project structure

StreamingTuner/
├─ StreamingTuner.uplugin
├─ Resources/                     # icons, thumbnail, cover
└─ Source/
   ├─ StreamingTunerRuntime/      # CVar registry, values struct, profile asset, BP API, shader‑aware pause
   └─ StreamingTunerEditor/       # settings page, details customization, asset factory & definition, styling

Compatibility

Built and tested against Unreal Engine 5.8. To support additional engine versions, set the matching EngineVersion in StreamingTuner.uplugin and rebuild.

Contributing

Issues and pull requests are welcome. For bug reports, please include the engine version and reproduction steps.

License

See LICENSE.

Author

Aleksey Karpov (IchiQ)

_{Copyright © 2026 Aleksey Karpov (IchiQ). All Rights Reserved.}