How to fix V-Ray GPU CUDA error 700, CUDA error 719, Optix error 7900

Overview

This article helps you identify and troubleshoot V-Ray GPU crashes that display CUDA or OptiX errors. It shows common error messages and explains when they typically occur so you can start troubleshooting.

Recognize common V-Ray GPU error messages

You may see one or more of the following messages when V-Ray GPU fails during rendering:

Root causes and solutions

CUDA and Optix errors may be encountered during production or interactive rendering with the V-Ray GPU render engine. These errors may be caused by several different factors, more information about each of them could be found below.

Note: Please follow the troubleshooting steps below in order starting from Step 1.

1. Using a not verified GPU driver version

Using the recommended driver is essential for a stable experience with V-Ray GPU. You can check the currently installed driver's version by going to: NVidia Control Panel > Help > System information. 

Watch a short video that shows how to check your NVIDIA driver version.


For the user's convenience, V-Ray GPU performs a graphics driver check at the beginning of the render and prints a warning message in the V-Ray Messages Log window if the current driver is different from the recommended one:

The current recommended NVIDIA driver for V-Ray GPU is listed at the top of the V-Ray GPU page. For the most stable experience, we advise using the recommended driver, even though newer versions may also work. 

Solution:

Install recommended GPU driver following instruction from this article: Install the recommended Windows drivers for V-Ray GPU.

2. Hardware malfunction 

The GPU may appear stable in everyday tasks but fail under heavy CUDA loads used by V-Ray GPU. Running stress tests helps reveal instability or OS issues that V-Ray may trigger.

To identify if this is the case, we recommend performing GPU (CUDA) stress tests with V-Ray Benchmark. In addition, you can also perform tests with software like FurMark, OctaneBench, RedshiftBench and etc.

• If any benchmark crashes, reports a CUDA error, or shows instability, the issue is likely a hardware or OS malfunction. V-Ray is not the root cause; it only exposes the problem under load.
• If all tests pass, investigate drivers, thermal limits, power delivery, or V-Ray configuration as possible causes. For additional background and troubleshooting tips, see Hardware malfunctioning article.

Solution:

Contact your hardware supplier or OS support to assist you on this matter.

3. Scene-related issue

Next, check whether the error occurs with specific projects only. To narrow down the possible cause render other projects and see if the same error occurs again or not. Also test rendering a new empty file - this is the simpest way to determine if the issue is general and occurs with any project, or it's scene-dependent.

• If the issue reproduces with every single scene file (including a new empty file), then the reason for the error is either the driver (1) or the hardware (2).
• If the issue reproduces with a specific scene only, then the issue could be caused by a bug or an insufficient memory . Proceed with step 4 to ensure the issue is not caused by insufficient GPU memory, and if that's not the case follow the solution below.

Solution:

Submit a ticket to our support team using the Chaos Support request form and attach:

1. Scene file (including assets) that reproduces the error. See also: How to upload files to Chaos Support.
2. VRayLog.txt (can be found in %temp% folder).
3. Describe steps to reproduce the issue (if error occurs with specific steps only).

4. GPU Memory (VRAM)

Another common reason for CUDA errors is insufficient GPU memory. 

Note: You may encounter crashes even though the GPU memory is not fully utilized (100%). This is happening when V-Ray requests more memory from the GPU driver than the currently available free one. For example, if the current free GPU memory is 4GB and V-Ray requests 6GB it will crash even before the memory is fully utilized.
 

To confirm if the issue is related to the GPU memory:

• Remove half or more objects from the project and try rendering. If the error stops, the scene likely exceeds available VRAM.
• Render the scene on a machine or GPU with more VRAM. If it succeeds, the issue is related to insufficient GPU memory.

Solutions:

There are several options that you may apply in case of insufficient GPU memory:

1. If you have multiple GPUs, render only on the GPU with the most available VRAM.
2. Optimize project to reduce GPU memory usage: check Optimize GPU memory usage in V-Ray article.
3. Upgrade to a GPU with more VRAM if the scene requirements exceed your current hardware capacity.
4. Render with cloud-based rendering Chaos Cloud service that Chaos provides, instead of using your local hardware.