Increase surface rendering speed

Do any of the following:

• Use single-sided instead of double-sided surfaces (which is the default) on the object’s Attribute Editor. The biggest speed gain is for the Maya hardware renderer.
• Tessellating large surfaces requires a lot of memory, so use several small surfaces instead of one large surface when you can. The renderer is more efficient with smaller surfaces.
• For Maya software rendering and Maya hardware rendering, use bump mapping instead of displacement mapping.
• For Maya software rendering, make bump maps flatter. To do this, reduce the value of the Alpha Gain attribute, which smooths the bump map and reduces the number of samples of adaptive shading. This technique only works when Edge Anti-aliasing is set to Highest Quality. The texture bump looks flatter when the Alpha Gain is lower.
• For Maya software rendering, turn on Use Displacement Bounding Box when using displacement maps.
• For Maya software rendering, use layered textures when possible, instead of a Layered Shader. (See Layered Shaders and 2D and 3D textures for more information.)
• For Maya software rendering, if you are raytracing the scene, set the Reflection Limit and Refraction Limit to the lowest values that produce acceptable results.
• To avoid re-tessellation of the same surface when using Maya software rendering, select Use File Cache in the Render Settings: Maya Software tab under Memory and Performance Options > Tessellation. When Use file cache is selected, geometric data is stored in a file in your system's temp directory.

  Operating system	Location of temp directory
  Windows	As defined by the TEMP environment variable Use echo %TEMP% to find the exact location
  macOS	As defined by the TMPDIR environment variable Use echo $TMPDIR to find the exact location
  Linux	As defined by the TMPDIR environment variable Use echo $TMPDIR to find the exact location

  You can change where the cache files are stored by changing where your TMPDIR or TEMP environment variables point to. Do not modify TMPDIR or TEMP in your system settings. Instead set these in a terminal or command window, and then start Maya from the window rather than from the desktop icon. If you are doing this often, you may want to create a startup script that sets these variables before it starting Maya.