If you are talking about 1 gpu doing all the work and the other gpu is just allowing access to its vram and not doing any computing then no. The processes get divide even-ish between the 2. Basic example would be 1 could be rendering let's say the land scape and terrain features and the other would be doing the assets, skybox, and any animations. Or another way that can be configured could be the both compute the same thing at the same time which won't relate to 2x performance really it's around 70% to 80% performance boost
Hi！ I successfully set up two A6000 GPU according to your tutorial and performed path tracking rendering for the project in UE5. The rendering speed doubled and was fast, but after only two or three hours, the rendering crashed.But when I Used only one GPU, everything ok. How should I set the parameters?😢
Thanks for this. I assume if I have 4 gpus this wont work since they need to be nvLinked? I do have an nvLink for my 3090s so might test that but have to turn off the other two :(
You don’t have to turn off the other two, but yea, you can only use the two on nvlink, and if you keep the others on you may have to specify which gpu(s) you’re using
Will the final packaged "game" require the same amount of Vram, as settings things up in UE5? I mean, if you approach the Vram limit with dual GPUs in UE5, will the final packaged "game" crash with one GPU ?
Wow this is incredible, thanks for sharing! Though the NVLink limitation means though that for consumer GPUs, the top-of-the-line configuration we can use is two 3090s, that should add up to a a decent 48 GB VRAM. Sad that Nvidia dropped support for NVLink starting with the 40 series, so this won't work for the 4090 unfortunately 😟😟
Alex thank you for the tut. Can you make a video of Multi-GPU in Blender with the same config PC for SilverDraft? A multi-GPU with RTX3090 instead of A6000 is possible ? Thanks!
Unfortunately, I don't think you can pool your Vram by combining 2 4090 because it does not have the nvlink/sli ability . Maybe it was done deliberately in order to not cannibalize their products such as the A0000 series cards
It has to have have an nvlink (a physical connection), and would only work with 2 of them. Also if they are the newest generation of a6000s it won’t work because they don’t supposing nvlink
Does it work on AMD GPUs? I tried in my setup and it kept saying : Training Process: RuntimeError: Found no NVIDIA driver on your system. Please check that you have an NVIDIA GPU and installed a driver
Hi Alex! Thank you for your video. You said GPU memory is going double when SLI. Are you sure? It is too good news for me to be a true. I have two rtx 3090 and I thinking now...
@@AlexPearce3d thats so unfortunate. there are so many people that would benefit of running dual 3060 for instance, or even dual 4090. but no, it feels they are excluding people who dont have dual ADA 6000 or dual 3090s out on purpose.
It doens't look like Alex replies to these messages but i wanted to try anyway - 5.4 unfortunately doesn't yield these results and i'm concerned that behind the scenes Epic, for some reason, disabled Multi-GPU and that would absolutely infuriate myself as someone who's invested thousand upon thousands in my solution.
Thanks for the tutorial, unfortunately on Nvidia control panel, the new drivers don't allow to configure SLI...
That's a great tutorial thank you,do you think it would work out with 2 GTX 1080 11 GB
Congratulations, very good!
Is there a way to do it for Twinmotion 2023.2? This 2 GPU process?
you can use multi Gpu in Chaos Vantage but in twinmotion a don't have idea
Multi-Process rendering for ue 5.3 ndisplay tutorial would be cool ;)
So this won't work without SLI on newer GPUs such as 4090 or 6000 ADA?
NVIDIA seems to have discontinued support of the NVLink for 4090.
@@amirierfan So I can't use 2 GPUs in Unreal without NVLink?
@hipninja1 correct
Does this give you more available VRAM or does it get "shared"?
If you are talking about 1 gpu doing all the work and the other gpu is just allowing access to its vram and not doing any computing then no. The processes get divide even-ish between the 2. Basic example would be 1 could be rendering let's say the land scape and terrain features and the other would be doing the assets, skybox, and any animations. Or another way that can be configured could be the both compute the same thing at the same time which won't relate to 2x performance really it's around 70% to 80% performance boost
will this work with a 3090 in 5.4 or 5.5? many thanks
Hi！
I successfully set up two A6000 GPU according to your tutorial and performed path tracking rendering for the project in UE5. The rendering speed doubled and was fast, but after only two or three hours, the rendering crashed.But when I Used only one GPU, everything ok.
How should I set the parameters?😢
You need a better motherboard and processor.
96Go Vram what a war machine you got dude!!! love that
May I ask what CPU and motherboard you have on that system?
Using the llama 2 70b machine for gaming. I would be very happy to test one of these out for you for a year or two.
Thanks for this. I assume if I have 4 gpus this wont work since they need to be nvLinked? I do have an nvLink for my 3090s so might test that but have to turn off the other two :(
You don’t have to turn off the other two, but yea, you can only use the two on nvlink, and if you keep the others on you may have to specify which gpu(s) you’re using
@@AlexPearce3d so I can use all 4? or just the two that are linked but then somehow command select which 2 to run?
did dual 3090 work? @@bensasi
Ah, that’s nvlink, not old sli. Curious if old sli would yield benefits. I have dual gtx 1070s
it is not working for 2 RTX 3060's .....
You need an Nvlink capable GPU
I dont think this works with RTX 6000 Ada's as they dont support NVLINK. Only the previous generation 6000 card.
I think you are correct
I'm lost? NVLINK is not only software so it needs a NVLINK adapter to tie in both cards?
Correct, NVLink is a piece of physical hardware that attaches to two cards
@@AlexPearce3d Thanks, just figured out after checking except I did not check before spending moneys on video cards! :p My Lazzy ass, Lesson learned
Thank you very much ❤, this is really working very well in UE 5.4.4 for VR
Will the final packaged "game" require the same amount of Vram, as settings things up in UE5? I mean, if you approach the Vram limit with dual GPUs in UE5, will the final packaged "game" crash with one GPU ?
Wow this is incredible, thanks for sharing! Though the NVLink limitation means though that for consumer GPUs, the top-of-the-line configuration we can use is two 3090s, that should add up to a a decent 48 GB VRAM. Sad that Nvidia dropped support for NVLink starting with the 40 series, so this won't work for the 4090 unfortunately 😟😟
Bro the eff you talking, they didn’t stop at 4090 they killed it in the Ada A6000 aswell. The professional line up killed NVlink aswell.
Hi Alex! What can you tell about rendering time in movie render queue? The same double result increase? I mean path tracing.
Alex thank you for the tut. Can you make a video of Multi-GPU in Blender with the same config PC for SilverDraft? A multi-GPU with RTX3090 instead of A6000 is possible ? Thanks!
I don’t have two 3090s i can test sorry!
i have the same setup i was also wishing someone can make one about blender did you ever find a video
@@mk8_it nope
@@studiodevis i found one but they keep taking my link down
Hi, in the blender documentation it mentions how to achieve this.
Can this be used to render VR?
I can confirm that, well working in vr ✅ (current version 5.4.4)
Does it work with games? I have two gpus... no sli nor nvlink
Thank you for the helpful information~ I have a few questions. Can the RTX 4090 also be used as a multi-GPU in the same way?
No
Hi. So would that mean both gpu vram would be used same time? Thinking 2 4090 vs 1 a6000 ?
Unfortunately, I don't think you can pool your Vram by combining 2 4090 because it does not have the nvlink/sli ability . Maybe it was done deliberately in order to not cannibalize their products such as the A0000 series cards
Will this work out of editor ? I want to run VR experiences powered by dual A6000's. Anybody know ?
Only two NVLink supported card can pair.
Hi, I can not find SLI option in 3d settings, but showing 4 RTX A6000 gpus. I am renting Paperspace for 4x gpus but utilizes only one. any advice plz.
It has to have have an nvlink (a physical connection), and would only work with 2 of them. Also if they are the newest generation of a6000s it won’t work because they don’t supposing nvlink
In the present year (2025), do two 3090 graphics cards still have an advantage over a single 4090 or 5090?
No, generally speaking one 5090 is better than 2x 4090s , one 4090 is better than 2x 3090s. So one 5090 is better than 4x 3090s.
And for ue this is especially true because they stopped supporting multi gpu setups from what I understand
@@AlexPearce3d Yes, the result I searched is that the multi-gpu feature has been removed in 5.5.👻
Does it work on AMD GPUs? I tried in my setup and it kept saying : Training Process: RuntimeError: Found no NVIDIA driver on your system. Please check that you have an NVIDIA GPU and installed a driver
No idea. Sorry :(
So is there a support for more than 2 GPU's? Say like 4 x GTX1080Ti's...
I doubt it because it relies on nvlink. You can research that term and see what the limits are but I only know of being able to use 2 at one time.
Seems it won't work for GPU Lightmass
Yes it should! In fact the best documentation for Multi-GPU I found was actually on the GPU Lightmass.
@@AlexPearce3d cool 👍
Hi Alex! Thank you for your video. You said GPU memory is going double when SLI. Are you sure? It is too good news for me to be a true. I have two rtx 3090 and I thinking now...
Yes it does double it!!
@@AlexPearce3d omg!!
what if I dont have SLI but have 2 gpus?
I don’t think there’s a way to make unreal work with it, without SLI, unfortunately :( otherwise I would have put 4 gpus in my machine!
@@AlexPearce3d thats so unfortunate. there are so many people that would benefit of running dual 3060 for instance, or even dual 4090. but no, it feels they are excluding people who dont have dual ADA 6000 or dual 3090s out on purpose.
96gb of VRam! That's crazy
I know right?!!!
You are swimming in technology right now :D@@AlexPearce3d
noT wORKING IN 5.4
That’s so frustrating. UE drives me crazy, every new release the deprecate important features for photo real rendering :(
Sorry to ask but are you using NVLink and what is your card?
It doens't look like Alex replies to these messages but i wanted to try anyway - 5.4 unfortunately doesn't yield these results and i'm concerned that behind the scenes Epic, for some reason, disabled Multi-GPU and that would absolutely infuriate myself as someone who's invested thousand upon thousands in my solution.
Aw man thats a bummer to hear! Leave it to epic to drop important features :(