Version: 2021.3
Language : English
Thread-safe linear allocator
Profiler overview

Customize allocators

Note: Not all platforms support this feature. Refer to platform specific documentation for further information.

To customize allocator settings you can either edit the configurable values through the Editor UI or supply them as command line arguments.

Use the Editor

  1. Select Project Settings > Memory Settings.
  2. Select the lock icon next to the value you want to edit.
Project Settings > Memory Settings, showing a selection of Player memory settings
Project Settings > Memory Settings, showing a selection of Player memory settings

Note: Refer to the previous individual allocator sections to see the fields customizable through the Editor UI.

Use command line arguments

To find the name of the allocator parameters you want to change, check the list of allocator settings the Editor and players print when they start up. For example, to change the block size of the main heap allocators, use -memorysetup-main-allocator-block-size=<new_value>

The allocator parameter names and their default values:

Allocator Description Parameter name Default value
Main Allocators The allocators Unity uses for most allocations.
Main Allocator The primary allocator Unity uses for most allocations.
Main Thread Block Size Block size of dedicated main thread allocator. memorysetup-main-allocator-block-size 16777216
Shared Thread Block Size Block size of shared thread allocator. memorysetup-thread-allocator-block-size 16777216
Gfx Allocator The allocator Unity uses for CPU allocations related to the Gfx system.
Main Thread Block Size Block size of the dedicated main thread Gfx allocator. memorysetup-gfx-main-allocator-block-size 16777216
Shared Thread Block Size Block size of the shared thread Gfx allocator. memorysetup-gfx-thread-allocator-block-size 16777216
Other Allocators
File Cache Block Size The file cache has its own allocator to avoid fragmentation. This is its block size. memorysetup-cache-allocator-block-size 4194304
Type Tree Block Size The type treess have their own allocator to avoid fragmentation due to many small allocations. This is its block size. memorysetup-typetree-allocator-block-size 2097152
Shared Bucket Allocator The bucket allocator that is shared between the main allocators.
Bucket Allocator Granularity Step size for buckets in the shared allocator. memorysetup-bucket-allocator-granularity 16
Bucket Allocator BucketCount Number of bucket sizes. memorysetup-bucket-allocator-bucket-count 8
Bucket Allocator Block Size Size of memory blocks used for buckets. memorysetup-bucket-allocator-block-size Editor: 8388608
Player: 4194304
Bucket Allocator Block Count Maximum number of blocks to be allocated. memorysetup-bucket-allocator-block-count Editor: 8
Player: 1
Fast Per Thread Temporary Allocators The Thread Local Storage (TLS) allocator that handles very short-lived allocations.
Main Thread Block Size The initial size for the main thread stack. memorysetup-temp-allocator-size-main Editor: 16777216
Player: 4194304
Job Worker Block Size Size of each job worker in the Unity job system. memorysetup-temp-allocator-size-job-worker E262144
Background Job Worker Block Size Size for each background worker. memorysetup-temp-allocator-size-background-worker 32768
Preload Block Size The preload manager stack size. memorysetup-temp-allocator-size-preload-manager Editor: 33554432
Player: 262144
Audio Worker Block Size Each audio worker thread’s stack size. memorysetup-temp-allocator-size-audio-worker 65536
Cloud Worker Block Size Cloud worker threads stack size. memorysetup-temp-allocator-size-cloud-worker 32768
Gfx Thread Blocksize The main render threads stack size. memorysetup-temp-allocator-size-gfx 262144
GI Baking Blocksize Each GI worker thread’s stack size. memorysetup-temp-allocator-size-gi-baking-worker 262144
NavMeshA mesh that Unity generates to approximate the walkable areas and obstacles in your environment for path finding and AI-controlled navigation. More info
See in Glossary
Worker Block Size
Nav meshThe main graphics primitive of Unity. Meshes make up a large part of your 3D worlds. Unity supports triangulated or Quadrangulated polygon meshes. Nurbs, Nurms, Subdiv surfaces must be converted to polygons. More info
See in Glossary
worker threads stack size.
memorysetup-temp-allocator-size-nav-mesh-worker 65536
Fast Thread Shared Temporary Allocators Fast linear allocator for short lived allocations shared between threads.
Job Allocator Block Size The round robin linear thread allocator Unity mainly uses for the job worker threads. memorysetup-job-temp-allocator-block-size 2097152
Background Job Allocator Block Size The linear allocator for the background workers that allows longer lived allocations. memorysetup-job-temp-allocator-block-size-background 21048576
Job Allocator Block Size on low memory platforms Platforms with less than 2GB memory use this size for both the job workers and the background jobs. memorysetup-job-temp-allocator-reduction-small-platforms 262144
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
Allocators
Allocators that Unity uses exclusively for the Profiler so that they don’t interfere with the application’s allocation patterns.
Profiler Block Size The block size for the main part of the Profiler. memorysetup-profiler-allocator-block-size 16777216
Editor Profiler Block Size Block size for the Editor part of the Profiler. This is not present on players. memorysetup-profiler-editor-allocator-block-size 1048576
Shared Profiler Bucket Allocator Shared bucket allocator for the Profiler and Editor Profiler allocators.

Not present on low memory platforms.
Bucket Allocator Granularity Step size for buckets in the shared allocator. memorysetup-profiler-bucket-allocator-granularity 16
Bucket Allocator BucketCount Number of bucket sizes. For example, if the value is 4, the sizes are 16, 32, 48 and 64. memorysetup-profiler-bucket-allocator-bucket-count 8
Bucket Allocator Block Size Size of memory blocks used for buckets. memorysetup-profiler-bucket-allocator-block-size Editor: 33554432
Player: 4194304
Bucket Allocator Block Count Maximum number of blocks to be allocated. memorysetup-profiler-bucket-allocator-block-count Editor: 8
Player: 1

Tip: To ensure your settings improve performance, profile the application before and after making changes. For more information, refer to the Profiler overview page and the package documentation for the Profiler Analyzer. Profiler Analyzer enables multiframe comparison, which is especially useful for highlighting differences in allocator performance. You can also check the memory usage reports. They are available in the log when you close the Player or Editor. To find your log files, follow the instructions on the log files page.

Storing and reading the settings

Unity stores allocator settings in MemorySettings.asset, which populates the boot.config file with the modified settings at build time. This means new settings take effect at every build.

In the Editor, the boot.config is in the ProjectSettings folder. It gets updated every time Unity imports or changes MemorySettings.asset. New values for the Editor only take effect on the next Editor startup.

Thread-safe linear allocator
Profiler overview