Optimizing memory and CPU for dynamic loading and particle effects on Android

[James72]

I'm developing a 2D mobile puzzle game in Unity, and I'm hitting serious performance issues on older Android devices; the frame rate drops significantly during scene transitions and when multiple particle effects are active. I've already reduced draw calls and texture sizes, but it's still not smooth. For mobile developers, what are the most effective optimization strategies specifically for managing memory and CPU usage during dynamic scene loading and visual effects on lower-end hardware?

[NatalieL]

Nice challenge. Start with a memory and timing audit on target devices (Unity Profiler + Android Profiler). Then move to a streaming approach: load the core scene asynchronously, then load additively for secondary areas while showing a loading screen. Keep a per-scene memory budget and use Addressables to unload assets you no longer need.

[Adam.S]

Memory planning: enable incremental GC to spread allocations; profile GC spikes and reduce allocations in Update by caching strings, avoiding new allocations. Use Addressables for asset loading, keep a hot cache for assets you reuse each scene, and unload unused assets as soon as a scene is switched.

[KennethZR]

Dynamic loading and VFX plan: designate a small 'streaming' scene that holds shared assets; use SceneManager.LoadSceneAsync for additive loading with allowSceneActivation=false to prepare a smooth transition; gradually activate; pre-warm assets during menus; for particle effects, pool systems and cap counts; consider using simpler shaders and lower-quality textures for active effects to stay within budget; recycle particle systems rather than instantiate/destroy; combine with emitter pooling.

[Mark_J]

Texture/shader tips: compress textures to game-appropriate formats (ETC2 for most devices, ASTC for newer phones), turn off mipmaps for UI textures, enable texture atlases to reduce draw calls, and use a simple unlit shader for most FX to cut CPU/GPU load. Also disable any post-processing on low-end devices; consider color grading only on high-end devices.

[Gary.W]

Question: what's your target device mix and Unity version? Are you using the built-in renderer or URP? Do you load scenes additively often? Do you have telemetry from devices? If you share those, I can tailor a concrete step-by-step plan.

[Hannah_T]

Practical quick wins: audit per-frame allocations and reduce them, test on a low-memory device; try a staged test: 30fps baseline, then drop draw calls further; replace particle bursts with baked sprites for less CPU usage; profile both memory and CPU on real devices.