Monitoring V-Ray GPU performance and memory usage on Windows

Introduction

By default, V-Ray GPU takes full advantage of the hardware's capabilities and efficiently utilizes all of the available processing power during rendering. However, when using Windows Task Manager's Performance graphs, you might notice that the information there doesn't correspond to the full utilization of the GPU. Windows Task Manager is not accurate in reporting Compute performance, it shows 0% usage on GPU2 and GPU3 in the example below. we recommend using an external tool like GPU-Z or MSI AfterBurner for monitoring GPU resources especially GPU usage.

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For the same example, here is MSI AfterBurner GPU usage graph. It accurately shows the usage of GPU 2 and GPU 3:

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Windows Task Manager

  • GPU Performance Graph: for GPU usage, not accurate for reporting compute(CUDA) performance.
  • GPU Memory Usage Graph: for GPU memory usage.
  • Dedicated GPU Memory: reports physical GPU memory for the GPU.
  • Shared GPU Memory: refers to a portion of the system memory that the GPU can borrow if needed, it is slower than dedicated GPU memory. It is helpful when using out-of-core rendering(Use System Memory for Textures).
  • GPU Temperature: for the temperature of the GPU chip. Also available under each device's name on the left side of the UI.

Stats tab in the VFB

For V-Ray 5.0 and later, the VFB has useful GPU stats for the current open scene, you need to start the IPR or Production rendering to see the information for the current scene. Some stats like Load % is only available when the Sampler is set to Progressive.

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Engine - shows the current GPU engine choice between CUDA and RTX.

Available Memory - The memory V-Ray GPU is able to use for this GPU. Note, this amount is lower than the total memory for this device as Windows WDDM mode takes a chunk of the GPU memory for this device. 3Ds Max(or any DCC) will take a chunk of the GPU memory for the GPU connected to monitors. Any open applications that use GPU memory like Photoshop, After Effects or Nuke will take a chunk of the available GPU memory for a GPU device.

Used Memory - the amount of memory V-Ray GPU is using for the current scene. the RTX engine usually uses more VRAM than the CUDA engine.

Load % - GPU usage in percentage

Performance - shows useful stats about progressive rendering.

Timing - render time after scene compilation

Memory tracking - detailed reporting of the scene elements using GPU memory like Textures, Geometry..etc Note, When using the "Use System Memory for Textures" Checkbox the stats tab might show incorrect data for GPU memory. This will be improved in the future.

 

Note: when using "Use System Memory for Textures" Checkbox the stats tab might show incorrect data for GPU memory. This will be improved in the future.

 

 

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