Memory Profiler module

There are two ways of analyzing memory usage in your application in Unity:

• Memory ProfilerA window that helps you to optimize your game. It shows how much time is spent in the various areas of your game. For example, it can report the percentage of time spent rendering, animating, or in your game logic. More info
  See in Glossary module: A built-in Profiler module that gives you basic information on where your application uses memory.
• Memory Profiler package: A Unity package that you can add to your project. It adds an additional Memory Profiler window to the Unity Editor, which you can then use to analyze memory usage in your application in even more detail. You can store and compare snapshots to find memory leaks, or see the memory layout to find memory fragmentation issues.

This page covers information on the built-in Memory Profiler module. For more information on the Memory profiler package, see the Memory Profiler documentation.

The Memory Profiler module visualizes counters that represent the total allocated memory in your application. You can use the memory module to see information like the number of loaded objects, and the memory that they take in total per category. You can also see the number of GC allocations per Profiler frame.

Memory profiling in the Editor

When you profile your application in the Editor, the Memory Profiler module reports higher data use than a similar profile of the application built on a target device would. This is because the Unity Editor uses specific objects that take up memory, and the Editor window itself uses extra memory.

Part of the extra memory use is because Unity treats objects like textures as read/write enabled in the Editor and keeps an extra copy of each texture on the CPU. This effectively doubles the reported memory use of textures in the Editor; for a more accurate idea of memory use by textures, profile a built version of your application running on the target platform.

Also, because Unity can’t cleanly separate the memory that the Profiler itself takes up from the Play mode’s memory, memory that the Profiler uses is displayed in the Profiler window. To remind you of this, a warning displays at the top of the Memory Profiler module details pane whenever you have the Profiler target set to Play Mode or Editor. For more precise numbers and memory usage for your application, you should profile your application on the target device and operating system you intend it to run on. For more information, see the documentation on Profiling your application.

Chart categories

The Memory Profiler module is divided into categories that display detailed information on where your application spends memory. You can also click a category’s colored legend to toggle its display.

Module details pane

There are two views available in the module details pane, located at the bottom of the Profiler window:

• Simple: Displays a high level overview of the memory statistics per frame
• Detailed: Captures a memory snapshot which contains more details on the memory that native objects used, including native references to them, and Unity’s different subsystems.

To change the view, select it from the dropdown in the top left of the module details pane.

Simple view

The Simple view displays an overview of how Unity uses memory in real-time on a per-frame basis. It breaks down the total memory that your application uses into a few major categories. The Total value is based on the System Used Memory Profiler counter, which indicates how much memory the operating system (OS) reports as being in use by your application.

Unity sets some memory pools aside for allocations to avoid asking the operating system for memory too often. The Profiler module displays how much memory Unity reserves, and how much memory Unity used at the time of the Profiler capture.

The Simple view displays the data collected within the System Used Memory Profiler counterPlaced in code with the ProfilerCounter API to track metrics, such as the number of enemies spawned in your game. More info
See in Glossary. This indicates how much memory the operating system (OS) reports as being in use by the app and corresponds to the Total value of the Total Committed Memory bar and the Total Memory Breakdown bar.

On platforms that support getting the total memory size of the application from the operating system, the System Memory Usage is over 0 and is the same size in a task manager.

The following reference table describes the statistics available in the Simple view, plus its corresponding profiler counter, and availability in Release builds. This information is also available via the ProfilerRecorder API and in the Profiler Module Editor so you can add them to a custom Profiler module.

Availability in Players

You can use the ProfilerRecorder API to access the Memory Profiler module’s counters in Players. The following example contains a simple script that collects Total Reserved Memory, GC Reserved Memory and System Used Memory metrics, and displays those as a GUI.TextArea. The Memory Profiler module information belongs to the ProfilerCategory.Memory Profiler categoryIdentifies the workload data for a Unity subsystem (for example, Rendering, Scripting and Animation categories). Unity applies color-coding to categories to visually distinguish between the types of data in the Profiler window.
See in Glossary.

using System.Text;
using Unity.Profiling;
using UnityEngine;

public class MemoryStatsScript : MonoBehaviour
{
    string statsText;
    ProfilerRecorder totalReservedMemoryRecorder;
    ProfilerRecorder gcReservedMemoryRecorder;
    ProfilerRecorder systemUsedMemoryRecorder;

    void OnEnable()
    {
        totalReservedMemoryRecorder = ProfilerRecorder.StartNew(ProfilerCategory.Memory, "Total Reserved Memory");
        gcReservedMemoryRecorder = ProfilerRecorder.StartNew(ProfilerCategory.Memory, "GC Reserved Memory");
        systemUsedMemoryRecorder = ProfilerRecorder.StartNew(ProfilerCategory.Memory, "System Used Memory");
    }

    void OnDisable()
    {
        totalReservedMemoryRecorder.Dispose();
        gcReservedMemoryRecorder.Dispose();
        systemUsedMemoryRecorder.Dispose();
    }

    void Update()
    {
        var sb = new StringBuilder(500);
        if (totalReservedMemoryRecorder.Valid)
            sb.AppendLine($"Total Reserved Memory: {totalReservedMemoryRecorder.LastValue}");
        if (gcReservedMemoryRecorder.Valid)
            sb.AppendLine($"GC Reserved Memory: {gcReservedMemoryRecorder.LastValue}");
        if (systemUsedMemoryRecorder.Valid)
            sb.AppendLine($"System Used Memory: {systemUsedMemoryRecorder.LastValue}");
        statsText = sb.ToString();
    }

    void OnGUI()
    {
        GUI.TextArea(new Rect(10, 30, 250, 50), statsText);
    }
}

The following screenshot shows the result of adding the script to the Tanks! tutorial project.

This information is available in Release Players, as are the other high level counters in the table above. If you want to see the selected memory counters in a custom module in the Profiler window, use the Module Editor to configure the chart.

Detailed view

The Detailed view provides a snapshot of your application’s current state. Select the Take Sample button to capture detailed memory usage for the current target. It takes the Profiler time to get this data, so the Detailed view doesn’t give you real-time details. After the Profiler takes a sample, the Profiler window displays a list view where you can explore your application’s memory usage in more detail.

Enable the Gather Object References setting at the top of the module details pane to collect information about what’s referencing an object at the time of the snapshot. The Profiler displays this information in the right-hand pane of the window.

The list view divides objects that use memory into the following categories:

• Other: Objects that are neither Assets, GameObjects, or components. This includes information such as the memory Unity uses for different systems.
• Not Saved: Objects marked as DontSave
• Builtin Resources: Unity Editor resources or Unity default resources, such as ShadersA program that runs on the GPU. More info
  See in Glossary you have added to the Always Included Shaders list of the Graphics settings.
• Assets: Assets referenced from user or native code.
• Scene Memory: Objects and attached components.

When you click on a GameObject in the Assets or Scene Memory list, Unity highlights it in the Project or Scene viewAn interactive view into the world you are creating. You use the Scene View to select and position scenery, characters, cameras, lights, and all other types of Game Object. More info
See in Glossary.

Note: In the Other category, memory reported under System.ExecutableAndDlls is read-only memory. The operating system might discard these pages as needed and later reload them from the file system. This generates lower memory usage, and doesn’t directly contribute to the operating system’s decision to close your application if it uses too much memory. Some of these pages might also be shared with other applications that are using the same frameworks.