---
title: "V-Ray GPU Setup"
canonical: "https://documentation.chaos.com/space/VMAX/113587140/V-Ray%20GPU%20Setup"
format: markdown
---
After changing this option, you need to restart the 3ds Max (or V-Ray Standalone) if it is running for the changes to take effect. If the V-Ray GPU render server is running as a Windows service, you may need to stop it from the Services applet in the Control Panel.

The Select devices for V-Ray rendering tool also allows for selecting GPU devices for denoising. 

Note that when multiple devices are selected for denoising, out of all the devices that match the query only the device with the highest compute capability is used for the denoising process.

> ✅ The asterisk (*) sign next to a GPU device's name in the list means that a monitor is connected to that GPU device. If two or more monitors are connected to the GPU device, there are 2 or more asterisks next to the GPU device name.
> ✅ 
> ✅ There is a tooltip that appears upon hovering over the asterisks that shows information on the GPU and number of monitors connected to it.


The Select devices for V-Ray rendering tool has less functionalities and different design in earlier versions of V-Ray. It is located again in **Start Menu > Programs > V-Ray 5.0 for 3ds Max > Select rendering devices for V-Ray GPU 5.0 for 3ds Max**.

 

![image](media://dd5f235c-9147-48ec-8fe9-6b22e2ba5ebe)


## **Balancing the GPU Load**

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If you have only one GPU on your system, you may find that the user interface becomes sluggish and unresponsive while V-Ray GPU is rendering. To alleviate this problem, reduce the **Rays per pixel** and/or the **Rays bundle size** / **IPR ray bundle size** parameters in the Performance tab of the V-Ray GPU renderer settings. For example, you can try values like **64/1** or **32/1**. This breaks up the data passed to the GPU into smaller chunks so that the user interface requests can be processed faster. Note, however, that this reduces the rendering speed. Turn on the statistics display to check the difference in render speed and to find the optimal settings for your system.

> Macro (anchor)




## **Hybrid Rendering with CPUs and the CUDA Engine** 

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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 CUDA 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](https://docs-chaos.atlassian.net/wiki/spaces/VMAX/pages/113586734) as the regular V-Ray GPU CUDA engine.

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## **References**

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The NVIDIA CUDA developer zone:[https://developer.nvidia.com/category/zone/cuda-zone](https://developer.nvidia.com/category/zone/cuda-zone) 

For more information on hardware recommendations, see the [Hardware Recommendations](https://support.chaos.com/hc/en-us/articles/4406890478865-Hardware-Recommendations) article.