VRAM Tweak

The mod is under active development. If you don't see any files on the download page, it means it's still under review or undergoing bug fixes. The mod is currently in beta.

If you are an AMD GPU user, please use Voxy Mod with caution. Although Voxy is an excellent LoD mod, it can cause VRAM overload for AMD users with less than 10GB of VRAM(especially when using PBR resource packs). Distant Horizons is recommended for AMD users.

We are waiting for Vulkan API, We look forward to seeing what other interesting changes the Vulkan API will bring.

After v0.1.2.7,We change License to GPLv2.

Overview

VRAM Tweak intercepts GPU texture creation at the OpenGL level via Mixin injection. It caps oversized texture atlases, downscales depth buffers, limits animation frames, and dynamically adjusts render distance — without modifying Sodium, Iris, or any third-party mod. Also includes a built-in VRAM forensics tool (AllocTracker) that intercepts every GPU allocation and classifies it by category and source.

Active Features

Feature How Status Atlas size cap Clamp texture atlas W/H ≤ maxAtlasSize ✅ Stable Depth downscale D32_FLOAT → D16_UNORM ✅ Verified Shadow map cap Limit shadow map resolution ✅ Stable Animation frame limit Truncate animated texture frame count ✅ Stable VRAM Governor Auto-lower render distance under VRAM pressure ⚠️ Under development Budget tracking Per-frame VRAM polling + configurable alert ✅ Stable AllocTracker Intercept every GPU alloc/free, categorize by type & source ✅ Stable

Conditional Features

Feature Trigger Format downscale (RGBA16F→RGBA8) Requires high-precision resource packs or shader packs

Note: Toggling the mod OFF in GUI only affects newly created textures. Restart the game to reload at full resolution.

AllocTracker — VRAM Forensics

Intercepts every glTexImage2D / glDeleteTextures call and classifies each allocation by category and source. Periodically writes aggregated snapshots to logs/vram-tweak/mod.log.

Example output:

[AllocTracker] ===== Snapshot t=0s ===== GL Used: 4971/8192 MB (60%) ── By Category ── TEXTURE_ATLAS 2772 MB (61%) RENDER_TARGET_COLOR 1571 MB (35%) ── By Source ── ATLAS_BLOCKS 1536 MB (34%) ATLAS_ITEMS 768 MB (17%)

Enable via Config → Diagnostics → VRAM AllocTracker, or /vramtweak allocreport.

HUD Overlay

Real-time overlay, each metric independently toggleable: FPS (smooth/avg/1%/0.1%), frame time, VRAM, atlas stats, alloc/free counts, governor status, alloc breakdown.

Commands

/vramtweak stats — VRAM + FPS stats /vramtweak dump — Ring-buffer CSV to disk /vramtweak hud — Toggle HUD /vramtweak benchmark — VRAM stress test (ON vs OFF) /vramtweak allocreport — Allocation breakdown by category + top-10 largest

Performance

HW: AMD R5 5600 + 32GB + RX 6650 XT 8GB
SW: MC 26.2 + Sodium 0.9.0 + Iris 1.11 + ScalableLux + 80+ mods

VRAM Breakdown (AllocTracker, maxAtlasSize=2048)

Source Size % Texture Atlases (blocks, items, misc) ~2772 MB 55% Iris Render Targets (G-buffer) ~1571 MB 32% Other (entities, GUI, font) ~180 MB 4% Untracked (driver, SSBO) ~448 MB 9% Total ~4971 MB 60% of 8GB

The atlas cap reduces individual atlases from 16384px to the configured limit. Iris G-buffers are the second-largest consumer and are not currently intercepted.

Requirements

Dependency Type Sodium Suggested Iris Soft (shader compat) Cloth Config Soft (GUI) ModMenu Soft (config button)

Platform: Windows, Linux
Java: 25+
GPU: AMD (auto-detect), NVIDIA (manual enable), Intel (safe skip)

Quick Start

1. Install Fabric for Minecraft 26.2
2. Install Sodium 0.9.0
3. Install Cloth Config API
4. Drop vram-tweak-*.jar into mods/
5. Launch → Mod Menu → VRAM Tweak → Enable

Config

{ "version": 1, "showExperimental": false, "vram": { "enabled": true, "shadowCapEnabled": true, "shadowMapMaxSize": 1024, "formatDownscale": false, "depthDownscale": false, "budgetTracking": false, "budgetWarningPercent": 80 }, "texture": { "animationLimit": false, "maxAnimationFrames": 32, "atlasSizeLimit": false, "maxAtlasSize": 4096 }, "diagnostic": { "enabled": true, "verificationLog": false, "allocTracker": false, "allocSnapshotInterval": 30, "logDirectory": "logs/vram-tweak" }, "hud": { "enabled": true, "offsetX": 4, "offsetY": 4 }, "governor": { "enabled": false, "hysteresis": 10, "minDistance": 4, "cooldownTicks": 100 }, "experimental": { "pinnedMemory": false, "pinnedMemoryMinSize": 1024 } }

Build

./gradlew build # Output: build/libs/vram-tweak-*.jar

Requires JDK 25+.

Architecture

Mixin Layer ├── MixinGpuDevice_VRAMOptimize → createTexture() format/size cap ├── MixinGameRenderer_Metrics → per-frame stats + alloc snapshots ├── MixinGlStateManager_AllocTracker → glTexImage2D / glDeleteTextures ├── MixinGlFramebuffer_AllocTracker → framebuffer attachment tracking ├── MixinSpriteContents_Animation → animation frame truncation ├── MixinOptions_RenderDistance → governor hook ├── MixinGui_Hud / MixinMinecraft_Hud → HUD overlay ├── MixinGlStateManager_PinnedMemory → AMD pinned memory (experimental) └── MixinGameRenderer_PerfMonitor → AMD GPU clocks Core (src/main) ├── allocation/ → AllocTracker: categories, tracking, logging ├── VRAMOptimizer / VRAMGovernor / MetricsEngine / VramFrameCounter ├── VerificationLogger / VramModLog / GPUDetector / VRAMConfig Client (src/client) ├── VramTweakHud / VramTweakCommand / ClothConfigFactory / ModMenuIntegration └── AMDPerfMonitor / PinnedMemory + PBO pool

License

GPLv2.