Memory usage too high

Note: This article applies to pre-1.4 versions of Corona Renderer only!

Rendering high-resolution images can sometimes be heavy on memory and even lead to system freezes or crashes. To reduce memory footprint, you can try following:

  • Reduce Internal res to 1 (This applies to pre-1.4 versions of Corona only. Internal resolution setting was removed in newer versions.)
    You can find it in Render Setup > System > Frame Buffer > Image filter

    Internally multiplies the rendered resolution by a given factor. Using value higher than 1 increases memory consumption significantly, but when used, it is possible to antialias very bright edges of lights. Use default value of 1 unless light edges antialiasing is needed, in that case set it to 2.
    See: I can see jagged edges!

  • Render Non-shading elements separately
    Each element in Corona Renderer, which is computed during rendering, consumes memory. More elements = more memory usage. This rule is especially significant while rendering high-resolution images.

    To reduce memory footprint while rendering high-resolution images, you can simply render all non-shading elements (masks, normal maps, zdepth, etc.) in separate rendering session using the "Render Only Elements" function.
    You can find it in Render Setup > Scene > General Settings > Render only elements button

    Renders only render elements which are not dependent on the beauty pass. This process is almost instant. The antialiasing of the output can be turned on/off with the checkbox to the right.
    For a list of all available render elements, see: 
    What render elements are there?

  • If you are using displacement, in Render Setup > Performance under "displacement" section set displacement's "screen size" to a higher value

  • Other possible causes of excessive RAM usage include rendering large amounts of objects or detailed mesh - in such case it is advised to optimize the scene.

See also: I am getting a sudden rise in RAM usage!

If the problem is caused by something else (for example it disappears after deleting some object or material), please report it as a bug using Mantis Bug Tracker or our Support System.

See: How to report issues?