8K Render fails

[ManMadeBlossom]

Hello,

my 8K image continues to crash after about 4-5 hours of rendering. I can render it in 2K without a problem. I do not use the AI Denoiser as I read that this can cause RAM issues. The first time it crashes it freezed completely and I had to reset my machine (I got a RAM error though). The second time C4D was just suddenly closed.
How can I reduce RAM and how do I get the image rendered? I have 64 Gig RAM and about 300mb VRAM left when I start the render.

I use some passes but I don`t know which part is responsible for the high RAM (or is it even a RAM problem)?

I have RTX acceleration activated, but that has probably nothing to do with the RAM?

Specs:

Windows 10
C4D R21
Octane 2020.1-R5
1x GTX 1080Ti
1x RTX 2080Ti

I would be very thankful for some help!

[aoktar]

Generate a report as in picture
https://drive.google.com/file/d/1UVYvqc ... p=drivesdk

[ManMadeBlossom]

Here is the Crash report. I figured out it happens right after the rendering before it starts with the multi-passes. The RAM seems to skyrocket in 2 seconds and it crashes. I try to save a 32Bit EXR file, tried wilt multi-layered file as well as with individual files, same problem.

[ManMadeBlossom]

Update: I just figured out it only crashes when I activate render passes. When I render and save the beauty only (as EXR) it works perfectly.

[ManMadeBlossom]

Update II: It crashes when I activate info passes (in this case Z-Depth) and/or Light passes. With beauty passes and object layer passes it works. What is this?

[bepeg4d]

Hi,
from the log, it seems that you have not followed point 1 and 2 of Ahmet’ screenshot
Anyway, you you need a lot of system RAM for handling high res frame buffer, especially with multi pass and AI Denoiser active. Each pass needs extra RAM.

If you cannot increase system RAM, the workaround is to use the Tiled Camera rig from Content Browser, to split the big frame buffer in tiles:

Note that you need to disable Vignetting and Post Effects, to have not visible seems when compositing back the entire frame buffer in PS or AE.

ciao Beppe

[ManMadeBlossom]

Hey bepeg4d,

many thanks for that workaround hint, I will try that.

Hmm, but I activated all these checkboxes and reproduced the crash. How do you assume that I ignored these steps?

Here is the last crash report.

During the rendering my RAM has a usage of about 30 Gig overall (C4D about 25 Gig). It crashed when I only activated one more pass (depth). Does this depth pass actually consume 30 Gig of RAM?
I don't even use denoise in this rendering.

[aoktar]

Not RAM, VRAM.
Leaving 300mb free for VRAM is too low for this case. It may not be enough for for some temporal operations and bumm

Look for ways to get more empty space on VRAM