System

The System section allows you to set graphics card options, memory limits & sound settings.

If your hardware does not support some of the options described on this page, then they will either not show up or be corrected on startup.

Preferences System section.

Cycles Render Device

Changes the computing device the Cycles render engine uses to render images. Cycles can use either the CPU or certain GPUs to render images, for more information see the GPU Rendering page.

None

When set to None or when the only option is None: the CPU will be used as the computing device for Cycles.

CUDA

If the system has a compatible Nvidia CUDA device, it will show up an option for rendering with Cycles.

OptiX

If the system has a compatible Nvidia OptiX device, it will show up an option for rendering with Cycles.

OpenCL

If the system has a compatible AMD OpenCL device, it will show up an option for rendering with Cycles.

Distribute Memory Across Devices

Allocates resources across multiple GPUs rather than duplicating data, effectively freeing up space for larger scenes. Note that in order for this option to be available, the GPUs must be connected together with a high bandwidth communication protocol. Currently only NVLink on Nvidia GPUs is supported.

Memory & Limits

Undo Steps

Number of Undo steps available.

Undo Memory Limit

Maximum memory usage in Mb (0 is unlimited).

Global Undo

This enables Blender to save actions done when you are not in Edit Mode. For example, duplicating objects, changing panel settings or switching between modes.

Warning

While disabling this option does save memory, it stops the Adjust Last Operation panel from functioning, also preventing tool options from being changed in some cases.

For typical usage, its best to keep this enabled.

See also

Read more about Undo and Redo options.

Console Scroll-back Lines

The number of lines, buffered in memory of the console window. Useful for debugging purposes and command-line rendering.

Texture Time Out

Time since last access of a GL texture in seconds, after which it is freed. Set this to 0 to keep textures allocated.

Garbage Collection Rate

Number of seconds between each run of the GL texture garbage collector.

VBO Time Out

Time since last access of a GL vertex buffer object (VBO) in seconds after which it is freed (set to 0 to keep VBO allocated).

Garbage Collection Rate

Number of seconds between each run of the GL vertex buffer object garbage collector.

Video Sequencer

Memory Cache Limit

Upper limit of the Video Sequencer and Movie Clip Editor memory cache (in megabytes). For an optimal Clip editor and Sequencer performance, high values are recommended.

Use Disk Cache

Writes cached strips to disk which can store a lot more than RAM. To use the Disk Cache, this option must be enabled, the Disk Cache Directory and Disk Cache Limit set, then save or reopen the existing blend-file.

Directory

The location on disk to store the cache.

Cache Limit

Upper limit of the Video Sequencer’s disk cache (in gigabytes), setting to zero disables disk cache.

Compression

The level of compression to compress image in the disk cache. This has a trade off between saving disk space and requiring more processing. The more compression used requires faster disk write/read speeds and more CPU usage.

Proxy Setup

When and how Proxies are created.

Automatic

Build proxies for added movie and image strips in each preview size.

Manual

Set up proxies manually.

See also

Sequencer Cache Properties

Sound

This panel contains the sound settings for live playback within Blender and are only available with SDL or OpenAL. To control these settings for exporting sound see the Encoding Panel and Audio Panel.

Audio Device

Sets the audio engine to use to process and output audio.

None

No Audio support (audio strips can still be loaded normally).

SDL

Uses Simple Direct Media Layer API from libsdl.org to render sounds directly to the sound device output. Very useful for sequencer strips editing.

OpenAL

Provides buffered sound rendering with 3D/spatial support. Used for 3D source support by speaker objects.

Channels

Sets the audio channel count.

Mixing Buffer

Sets the number of samples used by the audio mixing buffer. Higher buffer sizes can cause latency issues, but if you hear clicks or other problems, try to increase the size.

Sample Rate

Sets the audio sampling rate.

Sample Format

Sets the audio sample format.