Rendering with Arnold

[alexis.stallman]

Hello, I am trying to render a scene with arnold, but it keeps getting aborted.  I have seen this error before, but restarting the computer fixed the issue, however that is not working now.  Please help!

# Warning: [gpu] multiple GPU render sessions in parallel not supported #
# Error: line 1: RuntimeError: file <string> line 2: Maya command error #

Sequence rendering aborted

[Christoph_Schaedl]

Does your system have multiple graphics cards? How much cards are listed in the Rendersettings?

[Stephen.Blair]

# Warning: [gpu] multiple GPU render sessions in parallel not supported #

This means that there are multiple GPU render sessions running. GPU doesn't support multiple render sessions.

So, it sounds like you have one GPU render already going, and then you start another with Render Sequence.

[MikaelAndersson1467]

I am having the same problem, "multiple GPU render sessions in parallel not supported". Problem came with Maya 23. I am using Render Setup for different passes/render (AO, ALPHA and such). What else could be running? Nvidia drivers are also updated. 

[Stephen.Blair]

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@MikaelAndersson1467 wrote:

I am having the same problem, "multiple GPU render sessions in parallel not supported". Problem came with Maya 23. I am using Render Setup for different passes/render (AO, ALPHA and such). What else could be running? Nvidia drivers are also updated. 

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But how are you rendering? Render Sequence while the Arnold IPR window is running? Or while a Material Preview is rendering? That's the kind of thing that triggers the message.

[MikaelAndersson1467]

I was using the Arnold Render View window. Tested a batch render and recieved an alpha but with watermark stamp? Thanks for quick respond. Any other suggestions?

[MikaelAndersson1467]

When restarting Maya I am allowed to render one layer but when manually selcting another Render Layer, adding a "collection" and start rendering the message re-apperas (and GPU starts working judging from the sound). This process has been working excellent for many years. 

[MikaelAndersson1467]

Looks like shifting between CPU and render a few %, stop and toggle back GPU temporary solves the problem and rendering of a single layer starts again. 

[dave.cooleyVKJNJ]

I just updated my Arnold and Nvidia drivers and was getting the same error message. The CPU/GPU switch did stop the error message.

I have dual 3080 machines as well as a 4080 in another machine. Both gave the same error after updating.

I was trying to render a scene that had render settings already set to GPU.

It may be making a new scene, and importing the old scene into a new May scene could fix the issue.

A new Maya scene did not have this error.

As always, try to delete the preferences folder as well. it may be carrying old data.

[EPX株式会社]

I had the same problem with the maya2020 and Arnold 5.2.2.1.
After installing Arnold 4.2.4, the error disappeared.

I think this error occurs when Arnold5's GPU rendering a scene made with Arnold 4.

[didriklep]

This is still happening. We've yet to see a fix...

It tends to happen when you launch one or two programs in the background that may hog GPU performance, but it doesn't "reset" when you close them down. Like the others say, you have to do the CPU/GPU device switch to try and force it, or restart. edit: This is also a horrible option as it just causes a crash half the time I do it.

Not related to drivers or anything. Happens on all my different PCs.

Come on now.. 1 year and counting, Autodesk..