V-ray Next GPU not using all available GPUs

I have a PC with Threadr 1950X, 64Gb di RAM, 4xNVIDIA GeForce GTX 1070.

I have observed that in many scenes V-Ray Next GPU is only using cards nr 1 and 2, although if scene is quite heavy.

I have no problems with Redshift.

have tried to disable CPU from “render devices select” with same result. Any feedback on this item will be greatly appreciated, thank you!

Try to increase Rays per pixel and Rays bundle size parameters.
Default values of those parameters are optimized for single/dual card machines, for more devices adjustment might be necessary.

Sorry for the troubles, this is unexpected, could you please share your vraylog.txt ? Its located in your \AppData\Local\Temp folder

and here is the log…
vraylog.rar (70.6 KB)

Thank you Svetlozar, I have tried to increase them to 64 and 256 respectivley, but it did not change the behaviour. Same result…

Please check with 3rd part tool like MSI Afterburner or EVGA Precision.
Ive seem the task manager reporting wrong GPU usage on many occasions.
If they report low usage as well, can you please send the scene with which this happens to support@chaosgroup.com?

Thanks,
Best,
Blago.

Thank you Blago, I have tried with asus GPU tweak II, and it is showing all 4 cards with GPU usage 100% - thank you for your support, I won’t have any trust on task manager from now on… Have a great day!