roblox-performance

name	roblox-performance
description	Use when profiling Roblox performance or diagnosing FPS, memory, network, mobile, or hot-path problems, including MicroProfiler and optimization.
last_reviewed	"2026-07-13T00:00:00.000Z"
sources	["https://create.roblox.com/docs/performance-optimization","https://devforum.roblox.com/t/full-release-of-parallel-luau-v1/1836187","https://devforum.roblox.com/t/best-uses-of-parallel-luau/3530516"]

Roblox Performance

When to Load

Use when profiling, diagnosing lag, optimizing hot paths, or setting performance budgets. Load if the user mentions FPS drops, memory issues, network bandwidth, or mobile optimization.

Quick Reference

Profiling Tools

• MicroProfiler (Ctrl+F6) — Per-frame breakdown: scripts, physics, rendering. Primary tool for finding what's slow.
• Developer Console (F9) — Stats tab: memory, network, render stats. Server Stats for server-side metrics.
• Script Profiler (Ctrl+Alt+F5) — Per-script CPU usage and heap allocations.

Performance Targets

Metric	Target	Hard Limit
Server heartbeat	< 16ms	< 33ms
Client FPS (desktop)	60	30
Client FPS (mobile)	45	30
Memory (mobile)	< 800MB	< 1.2GB

Optimization Patterns

• Throttle Heartbeat — Batch expensive work at fixed intervals (10/sec, not 60)
• Cache references — Store workspace lookups in variables, avoid repeated FindFirstChild
• Spatial partitioning — Distance-based activation instead of checking all entities
• Lazy loading — Stream content from ServerStorage as player approaches

Parallel Luau

• Use Actors only after profiling identifies isolatable CPU work.
• Workers compute; synchronize before restricted DataModel writes.
• SharedTable and mutexes add coordination cost; they do not replace ownership boundaries.

Object Pooling

-- Core pattern: pre-clone, reuse, avoid GC pressure
local Pool = {}
function Pool:get(): Instance
    return table.remove(self._available) or self._template:Clone()
end
function Pool:release(obj: Instance)
    obj.Parent = nil
    table.insert(self._available, obj)
end

StreamingEnabled Essentials

• On by default for new places. Only BaseParts stream; Folders, ModuleScripts, RemoteEvents load at join.
• Streamed-out = parented to nil, not destroyed. Luau refs persist if it streams back.
• Config: StreamingTargetRadius (start 256, tune down for mobile), StreamingMinRadius (~64).
• Gotcha: FindFirstChild("DistantPart") returns nil if streamed out. Use WaitForChild with timeout.

Mobile Quick Wins

• Keep < 5000 visible parts. Textures max 512x512. Cap particles at 50 emitters.
• Use CanvasGroup for UI batching. Consider disabling GlobalShadows.

MCP verification: collect a baseline and inspect runtime counters after changes. Need more detail? Load references/full.md for the complete reference with code examples, API tables, and edge cases.