V-Ray's GPU engine utilizes the graphics cards' CUDA and RT cores by rendering under the CUDA and RTX modes. By default, V-Ray takes full advantage of the hardware's capabilities and efficiently utilizes all of the available processing power during rendering.
However, when reading the Task Manager's Performance graphs, you might notice the information there doesn't correspond to full utilization of the GPU. So let's see how to read the performance graphs in order to monitor your GPU more accurately when rendering.
Note: Chaos does not specifically endorse any third-party applications and all of the information presented below should be viewed only as a practical example.
Monitoring V-Ray GPU CUDA performance
To get the actual CUDA cores graph, switch to Cuda from the dropdown menu. By switching to the "Cuda” option, the Task Manager displays how the GPU is utilized by engaging the CUDA cores in the rendering operation.
If you decide to inspect the performance of the graphics card during rendering, keep in mind that:
- Generally, the Task Manager is not considered to be an accurate tool for monitoring, but can be used for general estimations;
- If the graph shows significant spikes and dips, this could be caused by overheating, which in turn causes the card to "heat-throttle", thus decreasing the performance output.
Note: Rendering under the CUDA mode (Default graphs):
The default graphs barely show any performance being done by the GPU, aside from the Memory usage, which too is an indication that the current project is being handled by the graphics card.
Monitoring RT cores
Windows' Task Manager is unable to display the performance of the RT cores, which could be an inconvenience.
For that reason, an alternative solution can be third party applications, which do this task quite well.
An excellent monitoring tool not only for the RT cores, but for the GPU as a whole is the GPU-Z application. It displays advanced detailed statistics about the entirety of the GPU's performance including speed, memory usage, current load, temperatures and many others.