Multi GPU Rendering

[GriffDesign]

With the hardware workload on RTRT with larger models does Chief support multi GPU rendering or are there plans to in the future?

[Renerabbitt]

1 hour ago, GriffDesign said:

With the hardware workload on RTRT with larger models does Chief support multi GPU rendering or are there plans to in the future?

Some google searching will let you know that nearly the entire rendering industry is doing away with multi gpu rendering for a number of reasons.(namely because of how multigpu works outside of a bucket rendering)

only software I know of that really makes use of it is Thea 

 

[Kbird1]

Chief has never supported multi-gpu rendering eg SLI , made that mistake many moons ago myself, and I don't think CA has any plans to implement it, as Rene says it is slowly being faded out as modern GPUs are so powerful nowadays. ( as well as multi GPU's not be very cost effective , especially at todays price's )

 

M.

[GriffDesign]

Absolutely I know it is being faded out for gaming and most software, however I thought that since 3DS Max (at least as current as 3DS Max 2020), VRay (as current as VRay 5), Blender and Thea all do, as well as software I'm less familiar with such as Octane, Maxwell, CycleX, FStorm, these were all listed as having Multi-GPU support and show quite noticeable gains from even 2 GPUs, but seem to get good gains up to 4 GPUs when the gain per card seems to taper off. I would assume the limited gains are due to CPU limitations and these programs may or may not be relevant to our use case. They do however seem to do the same basic functions as the rendering programs we are more familiar with. Many of these seem to be able to take advantage of cloud based rendering from companies like iRender where a Threadripper maxed out system with 4x3090 runs $15/hr.

 

Perhaps adding cloud rendering is something CA could look at, but personally I would not use it outside of RT Walkthroughs. I would just like the power of 2x3090 here at my office. Mainly to work on larger models in PBR RTRT, or more specifically easing the strain of hosting zoom presentations while screen sharing a PBR RTRT in a large model, making real time changes to that model based on client feedback, while running multiple screens and having 12+ tabs of chrome open, and opening Paint3D to make a custom texture on the fly. Yes I can do that with a single 3090 and frequently do, but I close chrome, turn off my 3rd screen and still when making many successive minor changes or accessing the library while doing it, etc. I can get some noticeable slowdown on larger models (beyond single room K&B, or even large kitchen/living/dining with many windows ) and often switch over to another view to ease the workload, switching back to PBR RTRT when the changes are made to allow the client to see. 

 

Being able to direct Chief to use a specific graphics card, while sending zoom, camera, and alternate monitors to another GPU is something that would probably solve the issue much easier and more affordably. I know Lumion has the ability for you to specify GPU, but alas naturally will access the GPU connected to the monitor the program is started on if you don't. This would seem, I do not use Lumion, to allow exactly what I am wanting to do and would also allow a very affordable used 2080 to handle the minor tasks once you connect the primary and secondary screens to it while dedicating the entire 3090 to Lumion once the 3rd screen is only connected to the 3090. (or ideally Chief if that was or is already implemented)

 

After thinking about it that would seem to be a much better and easier to implement path than multi-gpu. 

 

EDIT: After a quick google search it does seem that you can assign Chief or (zoom, chrome and camera) to use a specific card. I will likely do that and expect to see a noticeable increase in performance during presentations.

 

https://www.chiefarchitect.com/support/article/KB-03140/forcing-chief-architect-programs-to-use-a-specific-graphics-card-in-windows-10-11.html#:~:text=To configure a program to,select the Graphics settings link.

[Kbird1]

I am sure there will be a few people interested in your efforts/plans going forward , but I'd suggest not spending too much until you know it will work.

 

The article you link to is (was/started as) more about helping Users get their Laptops to NOT use the iGPU and forcing Chief to use the Nvidia/AMD Card in the Laptop , and now in Win10/11 setting up GPU Scheduling , so I'd suggest calling Support and asking a few questions for sure.

 

M.

[GriffDesign]

Well it will likely be a week or two before I get into trying anything, as I am remodeling my house and my home office isn't in any shape currently for me to be breaking down one of my PCs and making changes. However, I'm pretty good at this kind of thing and think I shouldn't have an issue making it work at all actually.

 

For starters I'm going to try and just assign Zoom, Chrome, Camera and whatever else I think might be using GPU to the secondary card, without any need to alter any setting within or based on Chief itself. Just allowing the primary card to be as dedicated to Chief as I can and in theory freeing up resources that those other programs are taking. I'll definitely update here when I do but it's not something I'll get around to until probably mid-late Feb depending on how long this remodel takes and I am able to get my office back to normal and get all these extra boxes and assorted junk out of here. 

 

[VisualDandD]

Funny.  I just posted a thread on if anyone is using any virtual computer/cloud rending.   Running a rendering on a 3080ti which is going to take 2 days and looking for alternatives.

[GriffDesign]

Wow..... 2 days, damn. If you do a lot of these you may look into, I'm not certain but don't some of the cloud service host virtual machines that you can load all your software on? Never done it but I remember reading about someone who offered that. Still wouldn't be much faster as you couldn't use multi-gpu even in cloud, but at least you could rent out a 4090 to lower the time and free up your machine meanwhile (though you'd have to have 2 licenses to keep working I guess, and I have no idea if our licenses would allow this or if it would be a violation)

 

[Kbird1]

2 hours ago, GriffDesign said:

I'll definitely update here when I do but it's not something I'll get around to until probably mid-late Feb

 

Well I'm sure most of us will all still be here   , will be interest to hear ( for me anyway) how it all goes.

 

M.