GPU Rendering and cpu % utilization 100% ?

[GVANDERV]

Yes I can see the 3 graphics cards. As I mentionned, the GTX usage is between 95-98% when cuda mode enabled. It does also feels faster then when only cpu is activated. by the way, is there a way to know the rendering time ?



Will put the log in another reply. There is an error in the spawner at the beginning though

Qt: Untested Windows version 6.2 detected!
Successfully initialized spawner. Waiting for jobs...
Broadcasting TM_SERVER_STARTED after start up

[GVANDERV]

Finally I sent you the log by email

[Svetlozar Draganov]

Thank you very much for the information.
Would you please let us know also the exact V-Ray versions and the GPU-drivers-version?

[Svetlozar Draganov]

Would you please try to increase the following parameters as follows:
Ray Bundle Size 256
Ray Per Pixel 16


Please note that when V-Ray RT use Cuda or OpenCL mode the actual rendering is performed on the GPU-devices but all the tasks are prepared and monitored by the CPU.
The above two parameters determines the size of the tasks that the CPU send to the GPU - smaller values means that the CPU will communicate more frequently with the GPU device which will increase its usage and vice versa. On the other hand if the GPU devices are very very fast they will complete the tasks too quickly requesting a new tasks from the CPU and this might increase the CPU usage as well especially on not very complex scenes.

We are looking forward to hearing from you.

[GVANDERV]

Hi.

My version of VRAY is:

=========Plugin Information=========
Plugin: V-Ray for Rhinoceros
Plugin Version: 2.00.25251 (edu)
Host Application Version: 6.1 (x64)

Driver version is the latest for quadro: 347.88

Quadro Desktop/Quadro Notebook Driver Release 346 WHQL 347.88 March 19, 2015
Release Highlights:
ODE Driver
This is the second release for the R346 drivers, the seventh ‘Optimal Drivers for Enterprise’ [ODE]. ODE branches are dedicated to relatively long term stability for ISV certification, OEMs, and Enterprise customers.

New in Release 347.88:

[GVANDERV]

Concerning the modification to the performance settings at:

ray bundle size : 256 and Rays per pixel: 16

No impact on cpu usage but definetly on the gpu usage that is almost always at 100% and also it make the computer graphically very laggy when trying to moves windows or simply zoom on the in process rendered image.

thanks.

[GVANDERV]

I had the quadro drivers 341.44 before today. Now with the 347.88 and in OpenCL VRAY RT uses 50 to 60% of the cpu, comparing to the 65 to 85 before. CUDA still the same. This is without changing the ray and leaving it at 16 / 4

[savage309]

I had the quadro drivers 341.44 before today. Now with the 347.88 and in OpenCL VRAY RT uses 50 to 60% of the cpu, comparing to the 65 to 85 before. CUDA still the same. This is without changing the ray and leaving it at 16 / 4

This may be normal, especially if you are rendering relatively simple scene (so the GPU renders fast and the CPU has to prepare a lot of tasks and process a lot of results). Increasing rays per pixel / bundle size usually decreases CPU usage and increase the GPU one.