Native memory allocators reference

You can control how native memory is allocated through using command line arguments, or using the settings in the Unity Editor (Edit > Project Settings > Memory Settings). For information on how to customize native memory allocators, refer to Customizing native memory allocators.

Project Settings > Memory Settings, showing a selection of Player memory settings

The following table contains information about each allocator setting, plus their command line arguments, and their default values:

Main Allocators

These allocators are the ones that Unity uses for most allocations.

Allocator		Description	Command line argument	Default value
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` bytes
	Shared Thread Block Size	Block size of shared thread allocator.	`memorysetup-thread-allocator-block-size`	`16777216` bytes
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` bytes
	Shared Thread Block Size	Block size of the shared thread Gfx allocator.	`memorysetup-gfx-thread-allocator-block-size`	`16777216` bytes
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` bytes
	Type Tree Block Size	The type trees have their own allocator to avoid fragmentation due to many small allocations. This is its block size.	`memorysetup-typetree-allocator-block-size`	`2097152` bytes
Shared Bucket Allocator		The bucket allocator shared between the main allocators.
	Bucket Allocator Granularity	Step size for buckets in the shared allocator.	`memorysetup-bucket-allocator-granularity`	`16` bytes
	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` bytes Player: `4194304` bytes
	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.

Allocator	Description	Command line argument	Default value (in bytes)
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.

Allocator	Description	Command line argument	Default value (in bytes)
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 2 GB memory use this size for both the job workers and the background jobs.	`memorysetup-job-temp-allocator-reduction-small-platforms`	`262144`

Profiler Allocators

Allocators that Unity uses exclusively for the Profiler so that they don’t interfere with the application’s allocation patterns.

Allocator		Description	Command line argument	Default value
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 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 isn’t present in players.	`memorysetup-profiler-editor-allocator-block-size`	`1048576` bytes
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` bytes
	Bucket Allocator BucketCount	Number of bucket sizes. For example, if the value is 4, the sizes are 16 bytes, 32 bytes, 48 bytes, and 64 bytes.	`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` bytes Player: `4194304` bytes
	Bucket Allocator Block Count	Maximum number of blocks to be allocated.	`memorysetup-profiler-bucket-allocator-block-count`	Editor: `8` Player: `1`

Additional resources

Customizing native memory allocators

Native memory allocator examples