--- title: "V-Ray GPU Setup" canonical: "https://documentation.chaos.com/space/VMAYA/111738911/V-Ray%20GPU%20Setup" format: markdown --- This page help you configure rendering for V-Ray GPU. For help with common questions, please see the Frequently Asked Questions page. Overview Rendering with V-Ray GPU performs the raytracing calculations on the GPU devices installed in the system, rather than the CPU. Since GPUs are specifically designed for massively parallel calculations, they can speed up the rendering process by an order of magnitude. To enable GPU rendering, select the V-Ray GPU engine as the Renderer  in the VRay tab of the Maya Render Settings window. Additionally you can enable RTX  acceleration for NVIDIA RTX GPUs. You can use it with both Progressive and Bucket Sampler types. Supported Hardware and Drivers V-Ray GPU renders with the NVIDIA CUDA, NVIDIA RTX, and the AMD HIP platforms, as well as macOS' Metal and MetalRT. Below is a list of tests we have performed and the results: NVIDIA – When the engine is set to V-Ray GPU (with RTX disabled), the CUDA platform is used. It is supported only in 64-bit builds of V-Ray for Maxwell and later NVIDIA cards. See here if your card has the minimum required compute capability. NVIDIA RTX – When the engine is set to V-Ray GPU with RTX enabled, V-Ray GPU uses the RT Cores in NVIDIA RTX GPUs . Metal – The Metal technology is used for hybrid rendering when V-Ray GPU is set to (XPU) Metal . For M2 machines and earlier, Metal is also used for GPU Only rendering, utilizing the native Apple GPU cards. MetalRT – When the engine is set to V-Ray GPU with (GPU) MetalRT enabled, V-Ray GPU uses the native Apple GPU cards using the MetalRT technology, available for M3 and later. HIP – When the engine is set to HIP, the AMD HIP platform is used. HIP is currently supported only for Windows. Metal GPU/XPU support is available with Maya 2024 and later versions. Hybrid Rendering – Hybrid rendering allows V-Ray GPU to utilize the CPU/XPU as if it is a GPU device. V-Ray GPU supports rendering on multiple GPUs. See the sections below on how to choose devices to run IPR GPU on. V-Ray GPU requires compatible GPU device(s) for rendering. When rendering, the Maya output window and the VFB Log panel provide information about your current driver version. If your driver is not compatible with V-Ray GPU, you will find a message with the recommended driver version. The V-Ray GPU page on the Chaos website always lists the latest recommended driver. Тo use NVLINK on supported hardware, NVLINK devices must be set to TCC mode. This is recommended for Pascal, Volta, and Turning-based Quadro models. For GeForce RTX cards, a SLI setup is sufficient. Also note that to prevent performance loss, not all data is shared between devices. Choosing Which Devices to Use for Rendering You may not want to use all available GPU devices for rendering, especially if you have multiple GPUs and you want to leave one of them free for working on the user interface or you may want to combine your CPU and GPU together (see the Hybrid Rendering section below). To do this, you can use the Render Device Selection in the UI or find the tool: For Windows : vray_gpu_device_select from this location: C:\Program Files\Chaos\V-Ray\Maya 20nn for x64\maya_vray\bin (where 20nn is the Maya version) . The tool is also found in the Start menu > Select devices for GPU rendering. For Linux : start vray_gpu_device_select from this location: /usr/Chaos/V-Ray/Maya20nn-64/vray/bin (where 20nn is the Maya version) For macOS : start vray_gpu_device_select from this location: /Applications/Chaos/V-Ray/Maya20nn/vray/VRay.app/Contents/MacOS/vray_gpu_device_select.bin (where 20nn is the Maya version) The tool controls which GPUs are involved in rendering and denoising. After changing options, you need to restart Maya and/or any Standalone DR servers (if any are running) for the changes to take effect. If the Standalone DR server is running as a service, you may need to restart it. For help on choosing GPU devices with MEL, see the vray gpuDeviceSelect page. Balancing the GPU Load If you have only one GPU on your system, you may find that the user interface becomes sluggish and unresponsive while IPR is rendering on the GPU. To alleviate this problem, reduce the  Rays per pixel and/or the  Ray bundle size  parameters in the Performance section of the IPR renderer settings in the Maya Render Setup dialog. For example, you can try values like  64/1  or  32/1. 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 will reduce the rendering speed. Turn on the statistics display to check the difference in render speed and to find the optimal settings for your system. Hybrid Rendering with CPUs and the CUDA Engine V-Ray GPU can perform hybrid rendering with the CUDA engine utilizing both the CPU and NVIDIA GPUs. V-Ray can now execute the CUDA source on the CPU, as though the CPU was another CUDA device. To enable the hybrid rendering mode, simply enable the C++/CPU device from the list of GPU devices. The hybrid rendering mode does not require any special drivers. Furthermore, you can use the CPU as a CUDA device even if you don't have an NVIDIA GPU and/or NVIDIA drivers installed. Meaning, this mode can be used on computers that don't even have GPUs. The hybrid render engine running on a CPU supports the same features as the regular V-Ray GPU CUDA engine. Hybrid Rendering with XPUs and Metal V-Ray GPU can perform hybrid rendering on your macOS machine utilizing the XPU as if it is another GPU card. Set the V-Ray GPU engine to XPU (Metal) from the settings. This is the fastest mode for rendering, but it can slow down interactivity inside Maya. Image Sampler The V-Ray GPU Image sampler is controlled using the Samples Limit and Rays per pixel options , instead of the previous Min and Max Subdivs . This separates the Image Sampler settings of the V-Ray renderer and the V-Ray GPU renderer . Switching from one render engine to the other will adjust the Min and Max Subdivs or the Samples limit and Rays per pixel parameters to the corresponding values, so that the noise levels remain the same. Progressive Samples limit – Determines the maximum number of samples that each pixel in the image receives. V-Ray performs adaptive sampling on the image, trying to put more samples into areas that have more noise. If the Samples limit is set to 0, V-Ray renders with the default value of 2500. Noise threshold – The desired noise level in the image. If this is 0.0, the entire image is sampled uniformly until either the  Samples limit  is reached or the  Max. Render time  is reached. Max. render time (min) – The maximum render time in minutes. When this number of minutes is reached, the renderer stops. This is the render time for the whole frame; it includes any GI prepasses. If this is 0.0, the render is not limited in time. Ray bundle size – Useful for distributed rendering to control the size of the chunk of work that is handed to each machine. When using distributed rendering, higher values may help to utilize CPUs on the render servers better. Rays per pixel – The number of rays that are traced for each pixel during one image pass. The greater the value, the smoother the picture from the very beginning of the rendering with GI, but interactivity may be significantly diminished. Increasing this value also reduces amount of data transferred from the render servers back to client machine. Bucket Samples limit – Determines the maximum number of samples that each pixel in the image receives. V-Ray performs adaptive sampling on the image, trying to put more samples into areas that have more noise. If the Samples limit is set to 0, V-Ray renders with the default value of 2500. Threshold – The noise threshold that is used to determine if a pixel needs more samples. Rays per pixel – Controls the minimum number of rays traced per pixel. References The NVIDIA CUDA developer zone: https://developer.nvidia.com/category/zone/cuda-zone For more information on hardware recommendations, see the Hardware Recommendations article.