How many process instances can 3ds Max run in parallel?

[futengda]

I understand that the number of instances is directly related to the hardware capabilities of the computer, but I’m encountering a peculiar issue.

I have a Windows workstation with dual RTX 4090 GPUs and an Intel Xeon Platinum 8336C (32C/64T, 2.3GHz, 54MB, 230W) CPU. When I try to batch process models use `3dsmaxbatch.exe`(specifically, rendering images using the Scanline renderer), I find that everything works fine when running 10 batch tasks in parallel. However, when I increase the number to 20 batch tasks, all the batch tasks get stuck—yes, all of them. At this point, CPU, memory, and GPU usage are still very low, all under 10%.

Therefore, I’m wondering if 3ds Max has an inherent limitation on concurrency, because 20 batch tasks on my machine should not be causing a performance bottleneck.

3dsMax version is 2024

[futengda]

Another test I conducted was to open 20 instances of 3ds Max Batch. During this time, resource usage was below 10%. However, when I opened a 3ds Max instance with a UI, I found that although resource usage remained below 10%, the UI became extremely laggy and nearly unusable. This also led me to question whether 3ds Max has an inherent concurrency limitation.

[CAMedeck]

Can I ask why you are trying to run that many batch processes at once?  With Scanline, I can't imagine your computer taking terribly long to render a group of images.

Dual RTX 4090s and a Xeon Platinum CPU rendering to Scanline is like pulling a utility trailer with a Corvette.

[futengda]

@CAMedeck 

Thank you for your reply. I need to batch process a large number (tens of thousands) of .max model files, and the process requires using the scanline rendering results. Of course, the process also involves a large amount of vertex computation, which takes about 5-10 minutes per model. Therefore, to improve processing efficiency, I considered using`3dsmaxbatch.exe`. I want to process as many models as possible simultaneously to complete the processing of tens of thousands of models more quickly.

Also, why scanline? Because I only need a z-depth map, and I believe scanline is the fastest way to output the z-depth. Is my understanding correct?

[spacefrog_]

According to my experience , scanline only benefits from multiple cpu cores only up to some certain number
I guess using somewhere up to 6-8 cores will show some real speedup when rendering with scanline. I question all benefit above , because datamanagement overhead will become rampant or even some strange incompatiblities might appear.
In your case, with using such a high number of individual 3dsmaxbatch processes, eac h one still launches a complete, headless 3ds Max instance. Add all the scene loading effort, greed for system resources etc ,
Never tried this, but i'm not really surprised that the whole thing locks up  in the end ...

[futengda]

@spacefrog_ 

I understand that my current usage is somewhat unconventional, but imagine that in the future, my Max file processing capability will be offered as an open service for model processing. At that point, besides starting a 3dsmaxbatch instance for each model processing task, are there any more suitable solutions?