Mod Dependence：Harmony / https://github.com/KSPModdingLibs/HarmonyKSP

KSPPerformanceProfiler

Hotkeys

You can also open the panel from the green performance icon on the game's AppLauncher in any scene.

Requirements

• Kerbal Space Program 1.12.x (1.12.0 – 1.12.5)
• Harmony 2.x (000_Harmony) — usually bundled with ModuleManager, Community Category Kit, or KSPCommunityFixes

Installation

1. Download the ZIP and extract it into your KSP root folder so that the mod lands in GameData/KSPPerformanceProfiler/.
2. Launch the game and click the toolbar icon or press a hotkey in any scene.

A next-generation, low-overhead in-game performance profiler, micro-stutter hunter, and native Mono heap anti-stutter manager for Kerbal Space Program 1.12.x.

Works in every scene — Flight, Map, KSC, VAB/SPH, and the Tracking Station — and drills through KSP's native dispatcher to reveal the real Mod callbacks behind frame spikes. No more blind stutter hunting.

Features

1. Mono Heap Anti-Stutter Management

With many Mods installed, Mono garbage collection (GC Stop-The-World) is the leading source of micro-stutters. This Mod natively integrates resident heap protection:

• Permanent static GC root — the padded physical memory block lives in a static root reference. Even when GC runs, the block is never released or shrunk, pushing GC stalls from every few seconds to once every tens of minutes.
• Non-intrusive by design — does not pad automatically on first install; it only suggests a recommended value after a scene loads, and you apply it manually in settings or via a hotkey.
• Smart memory detection — detects your physical RAM (8 / 16 / 32 / 64 GB+) and recommends a safe padding size, always reserving at least 4 GB for the system and GPU.
• Fine-grained tuning — accepts any integer (MB), with [-1024M] [-512M] [+512M] [+1024M] step buttons and a one-click release to return memory to the system.

2. Frame-Spike Capture & Auto-Freeze

• Microsecond spike radar — automatically captures a frame's full diagnostic topology when its time exceeds 200% of baseline and 35 ms (or FPS falls below 15).
• Top-6 culprit ranking — lists the 6 heaviest entities in that frame, pinpointing class name, Mod assembly, lifecycle method, and whether GC caused it.
• Auto-freeze review — optionally pauses the physics engine and game clock at the moment of a severe stutter to preserve the scene; one click resumes.

3. Interactive Timeline Graph

• Dual-mode chart — a stacked area chart shows the cost breakdown across PartModules, plugin scripts, PhysX physics, GPU rendering, and engine scheduling; the FPS curve marks 60 / 30 / 20 FPS baselines plus the 1% Low smoothness metric.
• Hover inspection — hover any bar to see that frame's microsecond composition and per-module share.
• Single-frame lock — click an anomaly frame to highlight and review it in the analysis card below.
• Layer toggles — show or hide the module, plugin, physics, and GPU layers independently.
• GC markers — an orange ◆ above the timeline marks frames where GC occurred.

4. Smart Bottleneck Diagnostics

Automatically identifies your performance shortfall and suggests a fix:

5. Five-Level Drill-Down & Dispatcher Penetration

📦 Assembly (DLL)
 └── 📂 Subsystem (timing / vessel dynamics / celestial orbits / EVA / editor)
      └── 📄 Concrete type (class / component)
           └── ⚙️ Lifecycle method (FixedUpdate / Update / LateUpdate / OnRenderImage)
                └── ⚡ Dispatcher penetration (TimingPre, Timing1~5 → Principia, Scatterer…)

Dispatcher penetration is the core differentiator of this Mod. Traditional tools see only native black-box cost when inspecting TimingPre or TimingManager; this Mod drills directly into the underlying delegate call chain to surface the real Mod callbacks hidden behind the native dispatcher (e.g. PrincipiaPluginAdapter.Precalc).

6. Free Resize & Responsive Layout

• Free resize — drag the ◢ handle to resize; adapts to 1080p / 2K / 4K.
• Works everywhere — Flight, Map, KSC, VAB/SPH, and the Tracking Station.
• Position memory — window size and position are saved with screen-edge snapping, so the window can't be lost off-screen.
• One-click export — exports a full diagnostic report to GameData/KSPPerformanceProfiler/Logs/.

FAQ

Q: How much performance overhead does the Mod itself add? A: Virtually none. Core interception and rendering paths use a strict zero-allocation strategy, and UI refresh is merged with a 250 ms damper — the Mod's own cost is typically below 0.05 ms per frame.

Q: Why isn't heap padding applied automatically after installation? A: Modifying memory should be an informed, deliberate choice. On first install it only shows a one-time recommendation and never takes your physical RAM on its own; apply it manually in settings anytime.

Q: I already have MemGraph or HeapPadder — will it conflict? A: This Mod's heap padder fully replaces their core functionality. Remove the old versions to avoid multiple Mods requesting extra padded memory.

Q: I can't see the Mod icon in-game. What should I do? A: The Mod registers for all scenes. If the toolbar icon is pushed off-screen by too many plugins, press Ctrl + Shift + P or the numpad +.

License

MIT — free to study, distribute, and modify. PRs and issues are welcome.