Doe's NVlink work for VfR?

[Micha]

Hi,

I tested the memory usage and NVlink, but the rendering is stopped with the message:

"Cannot allocate memory for the progressive frame buffers. To reduce memory usage, reduce the number of render elements."

Before at the process window was shown:

"
Total memory for device 0 : 11264 MB, free 8376 MB

Building optimized CUDA kernel (0) for comp cap 7.5 for device 1...

PTX file generated with CUDA Toolkit v7.5 for CUDA compute capability 2.0. CUDA runtime version 7050.

Optimized CUDA kernel assembled successfully

Total memory for device 1 : 11264 MB, free 8376 MB

Maximum kernel work group size: 1024

Maximum kernel work group size: 1024

Querying NVLINK ...

NVLINK detected between 2 devices

Device 0 is using NVLINK with id 0

Device 1 is using NVLINK with id 0
"

Why there is no 22GB limit used?

-Micha

[savage309]

This message "Cannot allocate memory for the progressive frame buffers. To reduce memory usage, reduce the number of render elements." is for CPU memory, not GPU.

Otherwise NVLINK is used, your mem limit is close to 22GB (doesn't scale linearly completely).

Best,
Blago.

[Micha]

savage309 Hi Blago,

I tried an other test. I started a GPU rendering of one of my large projects where I know it works below 11GB. It's runs fine and the GPU usage is around 8GB. Than I started Photoshop CS4 and opened a few large images. The GPU memory increased until 11097MB and V-Ray crashed in the background. Should V-Ray not stay alive per NVlink memory?

[savage309]

This doesn’t seem like memory related crash.
best to send scene to support

Best,
Blago

[Micha]

Today seen at an other scene too. I have the feeling the memory isn't increased by NVlink. Is there any chance to see the memory usage monitored?

What means the Win 10 values? ("Gemeinsamer GPU-Speicher" means GPU memory of both cards.) It doen't look like I would expect.

[Peter.Chaushev]

Micha, could you please provide some additional info about the unhandled exception error?
- Are you able to reproduce it reliably?
- Does it occur only when attempting to render a specific scene?
- Is it reproducible after restoring the default render settings and switching back to the GPU engine (note that Environment, Camera and Render Output settings will be reset as well)?

[Micha]

Peter.Chaushev I can reproduce the problem quite easy - increase the complexity of a scene until it need 10GB VRAM and open Photoshop. Now open a few large images and the VRAM usage increase until 11GB -> crash at V-Ray, NVidia crashs too. There is no VRAM available above 11GB.

The NVlinked 2080ti are using the same memory amount for the rendered scene like the 1080ti. In my example approx. 8GB. I would expect that the 2080ti divide the memory usage so that the scenes needs approx. 4GB per card + the system usage.

Should I try an other driver? How doe's it looks at your machines, if VfR and NVlink is used?

[Micha]

Here tried to render a scene of 8 complex Rhino blocks at 2x2080ti and run against the limit. The scene with 6 Rhino blocks was working at 2x2080ti + 1x1080ti.

[Peter.Chaushev]

I have tasked my colleagues from our Support department to reach out to you for further assistance with the GPU memory issue.
Regarding the unhandled exception error, if you manage to reproduce it again, please share the info requested in my previous post.

Kind regards,
Peter

[Micha]

I have tasked my colleagues from our Support department to reach out to you for further assistance with the GPU memory issue.
Regarding the unhandled exception error, if you manage to reproduce it again, please share the info requested in my previous post.

Thank you for tasking your colleagues. I don't wrote anything new about the error because I suppose so the problem is caused by I have still 11GB available VRAM only. What I did - I filled the VRAM per Rhino below the 11GB limit and used Photoshop to fill the VRAM until the limit was reached - this caused a driver crash and the error. It shows, that there is no shared VRAM above 11GB available, not for the system, not for VfR. I'm very curious to get the shared memory working so that more than 11GB are available. Maybe the latest driver 430.86 is the problem.

[Micha]

Driver isn't the problem. Same available VRAM per NVlink and non NVlink, only the VRAM usage is the 100% same in NVlink mode, but no bigger scenes can be rendered.