Very long render times

[blinq]

I have problem with very long render times on V-Ray GPU. It happens only sometimes - I have to restart the computer and fore some time it goes back to normal. For example: usually I render a frame in 1 or 2 minutes but after some time the render time can go up to 20 minutes. Or more. After restart it goes back to normal.
I work on newest V-ray GPU, Max 2023, RTX 3080

Edit: It happens on different scenes. Exterior, studio etc.

[vladimir_krastev]

Hi are you sure you are not facing hardware issues? Have you monitored your GPU's temps after some time at full load?

[blinq]

Hi,
After an hour of rendering at 100% GPU the temperature is 55 celsius. So not bad I think. But the render time of a frame went up from 3 minutes at the beginning to 11 minutes. Every frame in the scene is similar - its just a turntable.

[vladimir_krastev]

Hi could you send us a scene that reproduces this issue for review? You can upload it here or use the support contact form.

[nicolas_fuminier]

Hi,
After an hour of rendering at 100% GPU the temperature is 55 celsius. So not bad I think. But the render time of a frame went up from 3 minutes at the beginning to 11 minutes. Every frame in the scene is similar - its just a turntable.

Does your GPU VRAM of each frame increase over time (until the moment where your GPU can't handle it anymore) ?
You may be suffering from a memory leak (Ornatrix memory leak, Phoenix foam memory leak ...)
Each new frame your computer will stack a bit of next frame VRAM onto the previous one, causing the VRAM needed to increase ech new frame.

It can of course be something totally different but the symptoms can match,

Nicolas

[blinq]

Hi, Nicolas.
That seems to be the problem - it's not releasing the memory. Before rendering (when Max was open) memory usage was 2311MB. During render of first frame it was 8130MB. But after the render finished the usage went down but only to 5681MB. After a few frames usage between renders was 6800MB and during render 9278MB. So it goes up. I'll try to catch the moment when render time will go up.

The frames are mostly the same - same scene, simple animation.

[nicolas_fuminier]

blinq,

- Do you use any third part plugin in your scene ? (Ornatrix, Phoenix, Forest Pack ... ?) The leak might come from here. (If so, can you give us the version of those plugin)
- Do you use Blackburner or Deadline to render ? If so, there is an option to reboot your 3dsmax after X frame or after a latency time. Rebooting your max reset the memory leak and allow you to continue your render without being needed in front of the application.

[blinq]

I;m using Backburner. But the problem is present even when I'm working on a scene, doing test renders etc. It's very annoying because I have to reboot often.
Even when I don't use any plugins the problem occurs.

[nicolas_fuminier]

blinq

Didn't had any experience with memory leak while working on a scene. Specially if you don't use any plugin.

You are on Vray 6 ?
Wich max version ?

Maybe your graphic card drivers is the issue ? Can you try with the 512.59 version from Nvidia (latest tested and approuved by Chaos)

[blinq]

V-Ray: 6 Hotfix 3
Max 2023
Drivers: 517.40

I'll try to install the older drivers.
Thank You.