Need help with installing a GeForce RTX 4090 and an RTX A6000

I hope I am posting this in the right place. If not, please inform me as to the best place to post this question.

I am building a new PC and want to use the 4090 for gaming and the A6000 for multimedia work (3D, Photoshop, video editing, rendering). I don’t want to use them together, so I don’t think I need to worry about SLI. I was planning to tell each multimedia program and game which GPU to use.

I know that if I load both drivers that there could be conflicts in the control panel features, but would they still work for what I want them to do?

Also, which GPU should I plug my two monitors into, or should I plug them into the back panel of the motherboard?

Thank you.

Nvidia’s official policy on mixing Geforce and Quadro cards here, indicates there is no definitive answer - you’d just have to try it and hope it does what you want.

“We recommend against using GeForce and Quadro cards in the same system as it may cause unpredictable results. As such this is not considered a supported configuration.”

The multimedia work you mention is going to benefit much more from the 4090 than the A6000, due to 50% more cores and a clock speed of 2235 vs 1410MHz. I’m guessing the showstopper for you around just getting two 4090’s and saving a lot of money over the A6000, is that you need the 48GB of memory it provides.

Regretably NVlink is no longer an option with the 4090, so no chance of gaining extra memory space there.

Thank you for the advice. I was wanting to get the A6000 because it was at the top of the list for Maya so I figured it was the best one, but if 2 4090s will give me the gaming and rendering power that I want, then I will probably go that way.

One other question: since the motherboard I want doesn’t support SLI, will getting two 4090s be worth it since I wouldn’t be able to use them both for rendering, or would I still be able to even without SLI function?

When you say, “the 48GB of memory it provides” do you mean that two 4090s will give me 48gb more of memory, or that I need to get more memory to use two 4090? I plan on having 128gb of RAM. Or am I just not understanding what you are saying? :)

I am new to building my own PC so there’s a lot of these little details that I don’t understand yet. Thanks again for the help.

If you don’t think you’re going to need more than 24GB for your rendering, then you’ll certainly benefit from the 4090.

What are your primary multimedia apps? Not all make efficient use of multiple cards and building a machine with more than one 4090, for GPU intensive work, the power supply will need carefull consideration. Given the money being spent, it might be wise to get professional help with the build.

Maya will certainly be able to use 2 x 4090’s efficiently and Da Vinci Resolve is another that uses multiple GPU’s well.

I have no affiliation at all with them, but Puget Systems have a wealth of technical articles that will benefit your hardware choices:

RTX4090 review

Testing 4090 GPU scaling 1-7 cards

are a couple worth looking at.

Edit: Just saw your extra question:

The GPU has onboard memory, which would be used as the working space for rendering scenes and plugin processing. The A6000 has 48GB, the RTX4090 24GB. Only you will know the type of work you’re doing, as to the amount of RAM you’ll require, but if you don’t need more than 24GB, you are paying a price, dollar-wise and performance-wise. Two 4090 will not give you 48GB directly, but will allow two seperate rendering processes using 24GB each. In the past, NVLink would have allowed both cards to be connected so that both setts of memory could be pooled, but this is no longer available.

See this article;


Maya says that I need at least 16 GB of RAM for regular projects, 32 for complex projects, and that it is rare that I will need 64 GB or more. I plan on making videos with Maya for youtube and assets for games, so I am guessing I will need as much RAM as I can get.

The multimedia programs I plan on using are Maya 2023, AutoCAD 2023, Photoshop, Dreamweaver, After Effects, Premiere Pro. Maybe some others like Unreal or Blender.

I have checked with a site where you put in all your hardware and it tells you how much power you need. I plan on getting a 1600 watt power source which is about 100 watts more than it says I need for everything I plan on having, so I am hoping I will have plenty of power.

I would love to get professional help, but my local shop closed down years ago.

Can Maya use two 4090s even if the motherboard doesn’t support SLI? I thought I need that to use two GPUs for things like rendering.

If I have 128 GB of DDR5 RAM in my system, would that, plus the onboard memory of the 4090, take care of my rendering needs, or is rendering done only on the GPU?

Thank you again. And thank you for taking time to explain things.

This is system (motherboard RAM), memory and a different thing to that mentioned in my edit above. After Effects/Premiere will use as much of this as they can and 128GB should be fine.

Generally rendering can be done either “software”, in which case the GPU plays no part and system RAM and CPU are used, or “Hardware”, where the GPU is used and is usually much faster, but is constrained to however much GPU memory is present.

SLI is not a requirement in Maya (and other renderers), in order to use more than one GPU.

Make sure you get a quality 1600W supply - rendering for hours is a significant load and the GPU scaling article I linked above, shows wall socket draw for two 4090 at about 900W.

Other serious consideration will be needed around cooling and physical slot layout on the motherboard, to be able to fit multiple cards. Also be carefull to check motherboard manuals around having 2 accessable 16x PCIe slots that are actually wired for 16x. Often a second 16x slot may only have 8x or 4x wiring.

Thank you for confirming what I thought I understood about RAM. Just found out moments ago that Maya has a renderer in it that I can tell to use CPU or GPU. Seeing as I will have 128 GB of system memory, would getting two 4090s even be worth it or offer any benefit?

If I don’t need SLI to use two GPUs for Maya, what would I need SLI for? All I’ve been able to find about that is I need it to use 2 GPUs. I’m not saying you are wrong, I am just curious as to what they could possibly mean. I’m so confused.

I plan on having an electrician come out and check to make sure my wires and system can handle that much power draw.

According to the manual the motherboard makers sent me, one PCIe is 16x with16x or 8x mode and the second is a PCIe 16x with 8x mode. From what I have been able to figure out, if I put in two 4090s, they would be right up against one another. Page 13 is about the PCIe.

If having two 4090s won’t give me an advantage over one 4090 and 128 GB of system memory, then I think I can save my money and make sure there is room around the GPU for cooling. What do you think?

Thank you.

As I mentioned, in many circumstances GPU rendering can be significantly faster, only you will know the value of this and you may want to either do some testing elsewhere before purchase, or find some reputable testing.

You can find detail here with respect to Maya’s Arnold renderer and SLI is not mentioned. NVlink is but as I said, is not supported beyond 30XX GPUs.

Building a serious multimedia workstation is not a trivial task and while I used to do this professionally, I’m not comfortable making specific recommendations - there can be subtle hard/software considerations that are not obvious at first glance.

I mean no disrespect when I say that this seems to be somewhat of a learning experience for you, but there is significant room for wasted money/time and disappointment in an unreliable result.

If you are keen to proceed, maybe just going with one GPU, but allowing for future expansion if necessary, may be the way to go. Careful reading of the Puget info and the specifications of their test hardware will be worthwhile.

This is a definite learning experience for me. I have already learned so much in just a week’s time.

Seeing as I can’t really make the setup I was planning, the 4090 seems to work well with Maya from what I have been able to gather, there probably won’t be enough airflow between two 3 slot GPUs, I’ll have 128 GB of system memory, and I have enough money to by all the parts if I just get one 4090, I think that is what I will do.

Am I correct in thinking that since I will have 128 GB of system memory to use for rendering, the difference between having a GPU with 48 GB of onboard memory and one with 24 GB won’t really matter?

Plus the max power needed for my planned setup with just one 4090 is 1200 watts. That should be nicer to my old house too.

Thank you so much for all your help and patience.

No. As I mentioned before, if you use the “software” renderer, you are using system memory and CPU - no GPU.

“Hardware” or “GPU” rendering will predominantly use the GPU and the VRAM on board it.

Right. Sorry. I meant that if I use the CPU option to render, it doesn’t matter what the GPU has since I won’t be using it to render therefore making the difference between the GPU with 48 GB of VRAM and the GPU with 24 GB of VRAM a moot point since I won’t be using either of the GPU VRAM. From what I understand. Or am I all turned around?


Thank you.

And thank you again for all of your great help.