Iray runs best on systems with abundant video memory. In the event of VRAM depletion, Iray will recruit system memory. Depletion of both VRAM and system memory may increase system instability and cause the program to crash.

For rendering of larger projects, keep an eye on the GPU memory gauge and do the following steps if it turns red:

• iClone Preference - Reduce Max Texture Size while loading the project and check to see if Iray is still rendering at the highest possible texture resolution.
• iClone Minimal Texture Mode - Reduce texture memory usage in iClone to dedicate more more for Iray.
• Iray Texture Compression - Instantly save 30%-40% texture memory without noticeable drop in quality.
• Custom Iray Texture Size - Designate the texture pixel sizes for the entire scene or for select materials from 4k to 64x64.

To know more about "How to Reduce GPU Usage for Iray Renders", please watch the Tutorial >

For hardware upgrades that can improve the overall raw performance, we recommend the following solutions:

• Acquire Nvidia graphics cards with the largest memory size.
  • We recommend Nvidia's newest flagship graphics cards: RTX-2080 Ti (11G), RTX-2080 (8G), GTX-1080 Ti (11G), GTX-1080 (8G), GTX-1070 Ti (8G), GTX-1070 (8G), TITAN RTX (24G) or CUDA Quadro Series Graphics Card (Up to 32G).
  • Iray Performance Benchmarks and Hardware Setup. Know More >
• Multi-GPU setups can improve render speeds by several factors but will not impact the overall size of video memory due to limitations of the current Nvidia graphics card architecture. We recommend assigning your master GPU to the one with the most VRAM.
  

  Check out multi-GPU processing with NV Link using Quadro series graphics cards: Know More >

For in-depth analysis on VRAM usage per scene and character, See Here >