Please read the V-Ray GPU Setup page prior to the FAQ.
Frequently Asked Questions
Which features are supported on the GPU?
V-Ray GPU uses a different code base compared to the V-Ray engine, which is optimized for the GPU hardware. It supports a subset of the features of the V-Ray renderer. For a complete list of supported features please check the Supported Features page.
Can I choose which devices to be used for GPU rendering?
Yes. There are instructions how to do that in the GPU Rendering section .
How can I check which devices on my system can be used for GPU rendering? Why isn't my GPU device(s) listed?
Check the list of devices by running the Select Devices for V-Ray GPU rendering tool. If you don't see your device on the list there (the list is empty), try updating to the latest video drivers.
Why does the UI of my OS becomes sluggish when I use GPU?
- If you have multiple GPUs, you can remove the GPU used for monitor/viewport from the devices that GPU uses for rendering.
- If you have only one GPU on your system, you can assign Low Priority to the device from the render device selection. You could also try reducing the "Rays per pixel" and/or the "Ray bundle size parameters" in the Performance section of the IPR renderer settings in the Maya Render Settings window. This will break up the data passed to the GPU into smaller chunks, so that the user interface requests can be processed faster. However note, that this may reduce the rendering speed.
How do I reduce the network bandwidth when using GPU with a heavy DR setup?
If you use many GPUs in DR nodes you may find that the network can become a bottleneck at some point, since the GPUs are producing data very fast. Increasing "Bundle Size" / "Rays Per Pixel" increases the size of the workload chunks that are being given to the DR nodes and helps reduce the communication between the client and the servers (you can try something like 192/32 or 256/64).
How do I check and reduce the GPU memory needed for my scene?
You can use free 3rd party tools like MSI Afterburner and EVGA Precision to monitor both GPU memory usage and utilization. IPR GPU also reports how much memory it uses for textures/geometry/light cache/etc in the V-Ray log.
Can GPU be used as production render?
Yes, but within its limitations .
How do I set up GPU as a the renderer?
When V-Ray is selected as your current renderer in Maya, you can choose between the regular CPU-based V-Ray engine and the V-Ray GPU engine from the VRay tab of the Render Settings window. With V-Ray GPU y ou can specify if you want to use the CUDA or RTX platform. All V-Ray engines support Production and IPR rendering modes. The production mode is not interactive like the IPR mode, but it allows you to render animations and save images.
Why does the bump look different with GPU?
V-Ray GPU is built for optimal performance on GPU devices. As a result, some features have slightly different implementations between V-Ray and V-Ray GPU and the rendered image may be slightly different.
Larger scenes cause a "Failed to allocate memory for buffer" error with V-Ray GPU. Why?
If you get the following error message, this means that some or all of your video cards do not have sufficient memory to load the scene.
Why is the GPU rendering not much faster than the CPU rendering?
The difference in render speeds depends on the video cards and the CPUs that are compared, as well as on the scenes used as benchmarks. It is normal to achieve a big speed boost with the GPUs compared to the CPU with some scenes and to have equal performance with others.
Can I use multiple systems with GPU devices to speed up my rendering?
Yes, you can speed up your rendering using DR on multiple systems with CUDA enabled devices.
Keep in mind that if some drivers may have limitations and may not be able to use GPUs if there is no monitor attached to the machine or you are logged in via Remote Desktop (for example). Check the GPU vendor documentation for more information.
Why do some parameters appear grayed out and can't be used?
Some parameters are hidden or grayed out in the interface if they are not supported in V-Ray GPU.
How is the memory utilized when rendering with more than one GPU card?
The GPU memory usage is limited to the device with least memory. For example, if the setup consists of three GPUs with 4, 8, and 12GB memory, only up to 4GB will be used. The same cap applies when using CPU devices for CUDA rendering.
Why can't I change the Bucket size when using the CUDA render?
The bucket size is automatically determined for GPU rendering for optimal performance.