Isadora crashing when trying to select a monitor on my second graphics card

trossenink

Does Isadora work if you have two graphics cards in a PC? I can send videos to monitors on my first card, but Isadora immediately crashes if I try to select a monitor on my second card.

CitizenJoe

@trossenink

Somewhere in the help section you'll find a note that says that you cannot use 2 GPU's with Isadora. It's not supported.

That said, I do it all the time on a Windows 10 PC.

To really get help, you're going to need to provide a lot more information about your system....

Cheers,

Hugh

DusX

@trossenink

Using multiple discrete graphics cards is not supported by Troikatronix. It can be possible, and in some cases may be a viable option for connecting additional displays, however, it is both untested and generally poorly performing. Isadora will use your strongest GPU for processing (On Windows you need to assign isadora.exe to use the preferred GPU), when some video needs to be sent to a secondary GPU, Isadora will pull back the texture from the primary GPU and load it to the destination GPU. This back-and-forth is slow, and for 99% of cases I have seen, you will have MUCH better performance using the best GPU you have access to, and extending its available outputs as needed (quadhead2go and other extenders are preferred).

To make it work (unsupported) you need to ensure you have the primary GPU assigned to isadora.exe (windows graphics setup), and you need to ensure that the same GPU is the primary GPU (I forget how this is done) in the Control Panel of the Graphics cards (if you have 2 nVidia cards, you set them up in the nVidia control panel, I don't think mixed brands will work). I can't help more than that, since I have dismantled my machine that had 3 nVidia cards.
Remember, if you build a project using this configuration we will not be able to provide support.

CitizenJoe

~~Isadora 3 System Requirements : TroikaTronix~~

Edited after @DusX commented...

trossenink

@citizenjoe

Thanks for the reply and info. I have matching dual NVIDIA GeForce RTX 3060 cards in a gaming PC for my setup.

I have seen this same limitation in regards to only working with one graphics card on most of the software now. (Resolume, Smode, Isadora...) It is frustrating because my project is one that will have many screens, up to 16+ and I have yet to find any way to put a system together short of multiple $30K media servers which baffles me.

I was hoping to find software that could handle 2 cards because I'm already using 2 monitors for my workspace and 1 card leaves only 2 outputs then. Even if I set up a second machine and use 1 monitor for workspace that leaves a paltry 3 monitors for output. And of course, as soon as I have multiple machines, synching it all becomes a new challenge.

I've seen the output extenders mentioned by DusX and others on forums, but what is confusing about that route is the cost for them. They cost more than just setting up a new PC with 1 card, so it appears that the only benefit is keeping it on 1 system, but at a serious cost hit? Even then, if I'm using 2 monitors for workspace, and 2 expanders, I have only 8 outputs for $5K machine.

Is this just a real world limitation I am discovering? There is no way to get more outputs other than a $5K machine with extenders or setting up many many PCs with 1 card and getting only 3 outputs per machine then figuring out how to synchronize them all through something like OSC?

Thanks!

Woland

Forgive me if I cover anything you already know below, but I wanted to try to write an answer that might be helpful to others with similar questions who might not have as much experience and knowledge about this particular subject yet.

@trossenink said:

I've seen the output extenders mentioned by DusX and others on forums, but what is confusing about that route is the cost for them. They cost more than just setting up a new PC with 1 card, so it appears that the only benefit is keeping it on 1 system, but at a serious cost hit?

The other benefit is you don't have to try to get multiple computers frame-synched (if that's needed for a particular project), which can be a nightmare. The time spent programming the communication system and setting up the networking between the multiple machines should also be taken into account, so in the end I wouldn't say it's drastically cheaper to use multiple machines in every case.

@trossenink said:

It is frustrating because my project is one that will have many screens, up to 16+ and I have yet to find any way to put a system together short of multiple $30K media servers which baffles me.

You are not going to be able to find a cheap, easy, and fast way to send separate video content to 16+ displays. (If you want to send the same content to all of the displays, or say, there are four groups of four displays that get the same content within their group, then signal splitters will make the setup much less expensive. Example: A laptop outputting a single HDMI signal that goes into a 1-to-16 signal splitter and then sends the same signal to all sixteen displays is a much cheaper setup than needing to send different video content to all sixteen displays.) The more complex a project is and the more it demands, the higher cost is going to be (no matter whether the cost is in expensive equipment, hiring someone to build and program a system, or time spent programming a trouble-shooting a less expensive but complex setup, etc).

There's the old saying: Cheap, Fast, Good: pick two.

You can find a solution that's cheap and fast, but it won't be good (somewhat of a hack-y setup with many possible points of failure).
- Using many computers and making sure they all communicate and synch up via OSC or timecode over a network.
You can find a solution that's cheap and good quality, but it will extremely complicated and slow to set up.
- Using a few of powerful computers each with a few devices like a Datapath fx4 or Matrox QuadHead2Go.
You can find a solution that's fast and good quality, but it won't be cheap.
- Expensive media server
- Using a single, very powerful computer with many devices like a Datapath fx4 or Matrox QuadHead2Go (but you may run into a limitation in terms of the total amount of pixels you want to push to all the displays vs what the graphics card can actually handle)

@trossenink said:

Is this just a real world limitation I am discovering? There is no way to get more outputs other than a $5K machine with extenders or setting up many many PCs with 1 card and getting only 3 outputs per machine then figuring out how to synchronize them all through something like OSC?

Yes, this is a real-world limitation you are running into.

CitizenJoe

@trossenink said:

<p>@citizenjoe</p>I've seen the output extenders mentioned by DusX and others on forums, but what is confusing about that route is the cost for them. They cost more than just setting up a new PC with 1 card, so it appears that the only benefit is keeping it on 1 system, but at a serious cost hit? <p>Thanks!</p>

With respect to @Woland, I think there's another option which is both reliable and cheaper than a second GPU: :
DeckLink Quad 2 – Tech Specs | Blackmagic Design

EIGHT outputs, which can also be inputs. It's a brilliant piece of gear.

It works well in Windows and with Isadora. It's a bit weird in that Windows doesn't see it as a display, but Isadora out puts to it and can see it in Stage Setup. There's a couple of minor inconveniences: Isadora doesn't always remember the correct screen order, but it's usually just one thing that gets swapped around; and Isadora doesn't always see the card upon start up. It always see it the second time for some reason. I filed a bug report.

I've been trying to find a great solution to the output problem for years and this may be it! In my last show I had 4 outputs from the 3090 GPU, 6 from the Decklink and the other 2 channels I configured as inputs. I use the Intel Iris integrated graphics for the control monitor. It purred like a kitten.

Hope this helps!

Cheers,

Hugh

trossenink

@woland said:

QuadHead2Go

Thank you woland. I appreciate the breakdown. It isn't good news, lol, but it is useful news. I'll look into adding screen extenders into the mix for now, but I'll need to network multiple computers also in the end no matter what. Back to seeing if I can get OSC working with Isadora. Cheers.

Fred

@trossenink

Lots of good info here already, but lots of outputs is expensive and difficult.

One thing to watch out for on the decklink solution, it is not a GPU and requires data move from the GPU down the PCie bus and then to the decklink card. The decklink has no processing power and the pathway is costly.

I would go with data paths and the biggest GPU there is. You could do a cheap solution with an RTX 4090 and these untested devices:

https://www.aliexpress.com/ite...

Should work substantially cheaper than a datpath but seemingly they can do the job, especially ecialy with Izzy in between to take care of geometry - lots of the cost of the datapath is the onborad processing and resampling. We dont really need that, but we do want quality wich is is likely not.

Edit: The video wall controller linked above is HD input only.

Here is one that takes 4k input and has 4 HD outputs (this works at a mx refresh rate of 30p)

https://www.aliexpress.com/ite...

Here is on that can do 4k 60 and 4 HD outputs

https://www.aliexpress.com/ite...

This one will do 4k 60p input and 4x 1080p60 outputs (but also up to 9 screens at other resoltuions)

https://www.aliexpress.com/ite...

The other issue you will find is nvidia consumer cards are limited to 4 4k displays. You could use one of these cards to get the 16 outputs you want 4 x 4k->4 HD outputs but then you have no control screen. As Isadora can preview video on the control screen you are still better off using a card that can also give you a control screen for the interface. The AMD PRO W6800 can do 6 4K outputs and is reasonably powerful (and is used in some expensive media servers.

Whatever card you use driving this many pixels uses a lot of power and any effects or processing you need will need to be provided for with both CPU and GPU power. With a system this size I would get a high end CPU and a lot of RAM as well, after that you also need a lot of cooling.

If you did make a system with 16 outputs using on eof the above video wall controllers, an AMD PRO W6800 and a mid level cpu like the i9-13900K, you could get the rig together for under 10k (including 16 cheap HDMI to SDI and SDI to HDMI convertors). This is an incredibly cheap way of solving that issue. The issues you have with using multiple GPUs are not limited to Isadora, touch designer has some good info and a few extra features to deal with mutliple GPUs (https://derivative.ca/UserGuid...) but the TLDR is that no images or GPU resources can be shared accross GPU's - it basicaly lets you run multiple copies of TD with each running copy bound ot a different GPU.

I am curious to see how you go with this - keep us updated.

DusX

@CitizenJoe I know you have experience making multiple graphics cards work together, and have had success using these configurations. Please feel free to share your knowledge about these configurations. In no way do I want to limit the sharing of techniques here :)

I have also had success with these configs, having had 3 cards working well in one machine running Isadora. In my case, I had 1 decent GTX card as my Isadora card, and 2 very inexpensive cards (all nVidia) connected for additional outputs. This config was good in that I had many physical outputs all seen as displays by the system. Only the GTX GPU was used for processing. For output, the texture was pulled back and passed to the cheap cards (that's why the cheap cards were great).
The downsides:
- a lot of overhead pulling the textures down and passing them to the other cards (very much like the BlackMagic option) this allowed decent framerates as long as I wasn't doing much processing.. it dropped fast when doing anything more than playback (this was running on an older machine as well).
- mostly untested, and not supported.