GPU Rrendering a few questions

[gadzooks]

We are planning on buying a machine to start our render farm. I have a few questions maybe someone can help me with

1. Now that Vray has hybrid rendering we are planning on getting a machine with these specs. Is this a decent render farm machine?

1 x Xeon E5-2680V4 / 2.4 GHZ 35 MB CACHE, 14 CORE
RAM 32MB
SSD 512 GB - HP Z TURBO DRIVE
NVIDIA GEFORCE GTX 1080 TI VIDEO CARD (for GPU Rendering)

2. Will Vray auto detect that this machine has a GPU card installed and is part of the render farm? Once you set them up?
3. When you select hybrid rendering as you preferred method and submit a rendering thru backburner will it take advantage of both CPU/GPU automatically? Or is there something else that you need to do?
4. also doing distributed rendering with Vray, will Vray use use both CPU/GPU if hybrid rendering is selected on all the machines that are taking part?

[savage309]

1. This is a very good processor. Check the http://benchmark.chaosgroup.com/cpu to get an idea of the performance.
2. Hybrid rendering works only with V-Ray GPU. Check supported features here https://docs.chaosgroup.com/display/...orted+Features. You will have to choose V-Ray RT CUDA and enable the C++/CPU device from the list of devices in 3ds Max.
3. You have to enable the C++/CPU device from the "Select Devices for V-Ray GPU rendering" app (ocldeviceselect.exe) - it comes with every V-Ray installation. The C++/CPU (Hybrid) rendering is new and is available as opt-in feature. This is all you have to do.
4. Yes, if the C++/CPU device checkbox is ticked and you use the RT render slave option, all CPUs and GPUs will be used.

Keep in mind that the hybrid rendering is V-Ray RT CUDA feature (it basically makes the CPU behaving like a regular CUDA device), not V-Ray Adv. Check the supported features first.

Best,
Blago.

[danio]

Somewhat on the same topic: aside from some unsupported features, is there any downside to CUDA on the CPU? Does it render at the same speed as the Adv production renderer?

Thanks!
Daniel

[savage309]

CUDA on CPU is completely different code base compared to Adv. It will render with different speed compared to Adv, but the performance of both should be comparable.

Best,
Blago.