Multi GPU on my desktop - question

Discussion in 'General Hardware' started by JrKingOfBeer, Apr 7, 2024.

  1. JrKingOfBeer

    JrKingOfBeer Member

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    GPU:
    ASUS ROG TUF 3080
    Hey fellas. I used to post under the jrkob pseudo but, not having posted in several years, I get an "insufficient proviledges to perform this action" when I try to post a new thread or answer any thread so I just created a new loggin.

    Here's my question. The specs of my desktop PC are:
    Asus ROG STRIX Z690E
    i7-12700K
    Asus ROG TUF 3080

    Because my CPU is a "K", it has an iGPU and therefore, my overall system has 2 GPUs: the iGPU, and the 3080.

    On laptops, in a case like this, the nVidia Control Center would have an option in the 3D Settings that would let me chose which GPU I was to use for which app. So in my case on my laptop, I parameter the 3D Settings such as I use the iGPU for everything except games.

    I would like to know if something similar is doable on my PC ?

    Here's the issue: at the moment, my monitor is connected to my 3080, therefore nVidia Control Center only recognises the 3080 obviously. I can also connect my monitor to the motherboard instead in which case the nVidia Control Center will recognise the iGPU only.

    Is there a way to connect all this in a way as the nVidia Control Center recognises both GPUs so that I can parameter their use the way I want ?

    Thank you.

    - Jean
     
  2. Desktops work different, you cannot use the iGPU if your plugged to the dGPU and vice versa. There's really no need to use the iGPU with a dGPU though.
     
  3. JrKingOfBeer

    JrKingOfBeer Member

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    Ha, ok. Thank you for the clear response.
    I wanted to do this in order to save on my graphic card. In particular I'm living in a fairly hot area, its fans are running almost always despite my best efforts to cool the whole PC. But, looks like it will have to run.
     
  4. Ah I see. Well I guess you could try undervolting the card if you wanted to, to try and make it run as cool as possible.

    Although even if you live in a hot area, having the fans run all the time sounds like there could be something wrong with the cooler seating or thermal paste, assuming the card has the feature where the fans spin up at only 60 C or so.
     

  5. JrKingOfBeer

    JrKingOfBeer Member

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    Thanks for the response. Here's a picture of my setup. The case is a Corsair 110Q Mid Tower, which as you can see is a relatively small for the hardware I have. This is intentional, I don't have a lot of space under my desk and this is the smallest ATX case I could find that would fit all this.
    Now obviously, I feel that cooling isn't the best. 3 fans in the front, 1 in the back. And you are right, I program my graphic card's fan so that they start spinning to keep 60C exactly.

    With that said, what I have just done just now, is in Armour Crate, increase the speed of the 4 chassis+CPU fans and it seems to be better. The graphic card seems to be able to maintain 55C without the fans spinning.

    In any case, do you have advises for me on things I could improve ? (I cannot put an AIO because cannot place fans on the top of the case, and also I have so far resisted the water cooling solutions, I try to keep it simple).

    [​IMG]
     
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  6. octoreach

    octoreach Active Member

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    Disagree.
    You can use both iGPU and discrete GPU if you wish to do so.
    Windows 11 allows you to configure which GPU shall be used for each app, similar on how this is done from NVCP on laptops.
    I posted something very similar to this topic, that you might find interesting: https://forums.guru3d.com/threads/i...-bios-uefi-when-using-a-dedicated-gpu.447969/
     
    Passus likes this.
  7. JrKingOfBeer

    JrKingOfBeer Member

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    Ok thanks, let me explore that. I'm running Win10 instead of Win11, not sure if this will change something if I use NVCP.

    But from a cable perspective, how do I connect all this ?

    I connect one HDMI cable between my dGPU and my monitor, and a second HDMI cable between my iGPU and my monitor ? My monitor has 3 HDMI input ports.

    Is this how I'm supposed to connect the monitor to my 2 GPUs ?
     
  8. octoreach

    octoreach Active Member

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    You have only one monitor, right? You don't need two connections. The iGPU can be used, if enabled in BIOS, even when it's not connected to your monitor.

    Just connect the monitor to your main discrete GPU, and make sure you have your iGPU enabled if you want to use it as well for certain hardware accelerated tasks (browsers, video editors, other desktop applications).

    But you won't ever deal with managing multiple GPUs in the NVCP like you would do on laptops. That won't show up in this situation.
    The management is done in Windows Graphics settings (see below) and the discrete GPU will be used for games without exception.

    This is the dialog you're looking for, but you don't need to touch it 99% of the time. I haven't ever encountered any issue with this when I was using both and lately I haven't kept iGPU enabled, for no particular reason.
    [​IMG]
     
    Last edited: Apr 7, 2024
  9. JrKingOfBeer

    JrKingOfBeer Member

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    @octoreach Thanks a lot for all this, the explanation is very clear, as well as the linked article. Yes I have a single monitor.

    Now here is what is happening. My expactation is that for small apps running on Windows (again, Win10 in my case), the iGPU would be used. But it seems that whatever app I am running, the dGPU is used instead UNLESS I force the iGPU to be used in the Graphic Preference menu under Power Saving. In other words, Windows seems to be using the wrong GPU by default. In fact, I can see in the Task Manager that whatever I do under windows, the load of the iGPU stays at a rock solid zero and all the work is done by the dGPU.

    Do you have any suggestion ?

    See below screenshot

    [​IMG]
     
  10. octoreach

    octoreach Active Member

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    @JrKingOfBeer since the dgpu is the one driving your display, it will always have a small load. I think it is also the GPU used by Windows' hardware accelerated UI things, and not sure whether that can be changed.
    But you can check for each application what Windows defaults to and from there also change between the Power Saving (igpu) and High Performance (dgpu).
    Not all applications use hardware acceleration, so for some you won't see any load on your igpu even if forcing Power Saving. It all depends.
     
    JrKingOfBeer likes this.

  11. GeRmAnOs

    GeRmAnOs Master Guru

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    GPU:
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    Bit weird but i have this dialog box on my ryzen 5900x and 6950xt, bug or what as i dont have any other GPU on my system.
     

    Attached Files:

  12. Don't know if it's only the pic but looks like GPU is sagging quite a bit, it might make the contact between heatsink and GPU chip less tight.
    Good dusting could be in order too.

    Oh. I was aware of the GPU selection being the same but didn't think it would output anything on a desktop PC if you choose a GPU to which the monitor isn't plugged.
     
  13. octoreach

    octoreach Active Member

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    Seems to be by design, I also have this with only one option (dgpu), that's it.
     
    Last edited: Apr 7, 2024
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  14. Freeman

    Freeman Master Guru

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    GPU:
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    what's your weather temps? Where u from
     
  15. JrKingOfBeer

    JrKingOfBeer Member

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    You're right ! I didn't notice before. It seems there was a cable pushing it down so I rearrange it. But in any case there is a good 3-4mm clearance between the heatsink and the graphic card. Thanks for spotting this.

    Thanks for the explanation. So it looks like I'm already doing the best I can in this respect.

    I'm living in Hong-Kong. I think in my room it can get up to 25-26 degrees and again, my ATX case clearly isn't the best for cooling, I realise this.

    Now guys, what I have done is increase the speed of all the chassis fans substantially (but not to the point where I can substantially hear them) and my graphic card hovers at 50C, meaning that the GPU's fans aren't spinning since I programmed them to kick in at 60C. Should I be happy with that ? My room temperature is 25C and my CPU is at 37C.
    I didn't realise that increasing the airflow in the case would have so much impact on the GPU's temperature. It's a 10C difference at least.
     
    octoreach likes this.

  16. octoreach

    octoreach Active Member

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    26 is not that hot and shouldn't normally pose a problem to cooling GPU and CPU. As I understand it, when measuring cooling performance, reviewers use the "degrees over ambient" metric, so then I would infer that this linearly increases with the room temperature. 2 degrees more of ambient temp should result in 2 degrees more of CPU/GPU temp, given the same cooling capabilities.

    I think you shouldn't care about managing and moving GPU loads of applications from discrete to integrated under these circumstances. This isn't the solution. The approach of providing more cooling, if needed, is the one I would follow. Hardware accelerated applications and the OS should never make the GPU too hot as they never put that much load. So they shouldn't concern you at all.

    Things you could try:
    • leave the GPU fans on their default setup: no custom curves or settings; I also have an ASUS card and never touched the GPU fan curve configuration and it cools it just fine. CPU and case fans are adjusted (or need to be) more often.
    • if the default GPU setup is not good enough I would say that it exposes another issue with your system: either problems with your GPU's heatsink or insufficient cooling, as you presumed. So solution is to provide adequate cooling by those means.
    To get a fair frame of comparison look up some reviews of the same RTX series model (maybe you are lucky and find exact same manufacturer and edition) and compare with your temperatures. It shouldn't be too far off. Compare the GPU temperature under heavy load in gaming or benchmarks (not synthetic, gaming ones) at max power consumption & full load. A game with ray tracing is an easy way to load up your GPU to the max. If temperatures there match reviewer's or don't deviate by a lot (disproportionately) then you're fine.
     
    Last edited: Apr 8, 2024
  17. JrKingOfBeer

    JrKingOfBeer Member

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    GPU:
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    @octoreach thanks for the suggestions !
    So my preliminary findings is that leaving the chassins fan on their default setups doesn't seem to work well. There are predefined modes for me to chose from, but the Standard Mode doesn't cool enough, and the Turbo mode is too noisy (this is after using the AI optimising tool in Armour Crate of course). So I have to make my own profile somehow in between both these modes and it seems to work.
    For the graphic card, reverting back to default cooling profile works ! Fans seem to kick in at slightly under 60C so under normal Windows use (as in non-gaming), the fan never spins. Which was also one of my objective to preserve the graphic card. So I got rid of my home brewed fan profile.

    Just to come back to my sagging graphic card. This bothers me a little. But given the weight of these cards, isn't this a little bit normal ? In any case would something like <this> solve my problem ? it's like a stand, adjustable in height.
     
  18. Freeman

    Freeman Master Guru

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    GPU:
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    maybe dual boot. One GPU for Integrated, One for 3080.
    yes, your fans should be running at startup. Download MSI afterburner and they will go default at 30%. As they should , because Hong Kong really seems hot. and its not thats its just hot, if your room is not in the ''shadow side'' of building its: unlivable.
    GPU does sag, just put some Costa Coffee stick in , whatever
    your PC sits in a corner, maybe put it up somewhere.
     
    Last edited: Apr 9, 2024

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