New Input System overview in Unity - Performance & Optimization

Performance: New Input System overview

MEDIUM IMPACT

This affects how quickly and efficiently user inputs are processed and how responsive the game feels.

Handling player input in a Unity game

Unity

void OnEnable() {
  var playerInput = new PlayerInput();
  playerInput.Player.Jump.performed += ctx => Jump();
  playerInput.Enable();
}

Uses event-driven input handling that triggers only on input events, reducing unnecessary checks.

📈 Performance GainNon-blocking input processing; reduces CPU usage and improves input responsiveness.

Handling player input in a Unity game

Unity

void Update() {
  if (Input.GetKeyDown(KeyCode.Space)) {
    Jump();
  }
}

Uses the old Input class which polls input every frame and can cause missed inputs or lag in complex scenes.

📉 Performance CostBlocks input processing until Update runs; can cause input lag especially with many objects.

Performance Comparison

Pattern	Input Checks	CPU Usage	Input Lag	Verdict
Old Input.GetKeyDown polling	Runs every frame	Higher due to constant polling	Higher due to frame delay	[X] Bad
New Input System event callbacks	Runs only on input events	Lower due to event-driven model	Lower due to immediate event handling	[OK] Good

Rendering Pipeline

Input events are captured asynchronously and dispatched to listeners without blocking the main game loop, improving responsiveness.

→Input Processing

→Game Logic Update

⚠️ BottleneckPolling input every frame in Update causes delays and missed inputs.

Core Web Vital Affected

INP

This affects how quickly and efficiently user inputs are processed and how responsive the game feels.

Optimization Tips

1Avoid polling inputs every frame; use event callbacks instead.

2Enable input actions only when needed to save CPU.

3Use the Profiler to monitor input processing times for responsiveness.

Performance Quiz - 3 Questions

What is a key performance advantage of the New Input System over the old Input class in Unity?

A It uses event-driven input handling instead of polling every frame.

B It requires less memory for storing input states.

C It automatically optimizes graphics rendering.

D It reduces the size of the game build.

DevTools: Profiler

How to check: Open Unity Profiler, record while playing, look at CPU usage and input event handling times.

What to look for: Lower CPU time spent in input processing and faster response to input events indicate good performance.