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pedroaab

Multiple different GPUs on Prepar3D v4

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Hello,

I'm not used to create topics, so I appologise if I commit any mistakes. I am now using Prepar3D v4 in my computer (Windows 10), usually with PMDG 737NGX and 6 displays. The main display is connected to a GTX 1070 graphics card, which shows the scenery. All the other displays are connected to the integrated video card (Intel Graphics 630). Usually I fly in windowed mode, with detached displays (overhead, DUs, radio panel...) distributed in the monitors connected to the integrated video card. I know that it can reduce the FPS, but most of the times they are around 25 FPS, which is good for me. I realised that a second dedicated GPU could improve performance, so I installed a GT 1030 that was not being used. However, if I use the same configuration with the monitors conneced to the GT 1030, the FPS drops to about 10 instead of increase, even with the fact that the GT 1030 is much better than the integrated graphics. A few months ago (I was using P3Dv3, not v4), in another topic, it was pointed out that the second GPU could half the bandwidth for each GPU, or the cause for the FPS drop could be the fact that the FPS is limited by 30 in NVidia Inspector. It makes sense, however, shouldn't I get the same FPS drop using the integrated graphics? I was thinking if the reason behind this is that both video cards use the same driver, so the system is using just one GPU to process data, which is not the case when I use Intel 630, but I'm not sure. If this is the cause of the FPS drop, If I change the GT 1030 to a Radeon (with similar performance, and assuming it can run with the GTX 1070) for the detached displays, is there a chance to get better FPS results in P3Dv4?

My specs are:

Gigabyte B250M Gaming 3

Intel Core i7 7700 Watecooled 

Zotac GTX 1070 8GB and Asus GT 1030 2GB

480 GB Sandisk SSD

32 GB of RAM at 2133 MHz DDR4

Thanks!

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The GTX 1030 is probably not much better than your onboard graphics. The 1030 was designed for simple workstation use only, not gaming. Typically, using different types of graphics cards at once cause all sorts of issues. You may have to purchase another 1070 to get it to work correctly. 

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I am using almost the same GPUs as you and I do not have your dramatic FPS drop.

Now I have one GTX 1070 and one GT 640, bith Nvidia cards.

You can see my setup here: 

http://www.flightsim4fun.com/b737-800-simulator.html

 

I do have reduced FPS, but it is more than good enough as the sim is smooth and without and stuttering.

 

 

 

 

Edited by roarkr

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4 hours ago, 19dcavscout said:

The GTX 1030 is probably not much better than your onboard graphics. The 1030 was designed for simple workstation use only, not gaming. Typically, using different types of graphics cards at once cause all sorts of issues. You may have to purchase another 1070 to get it to work correctly. 

Could another 1070 make a significant difference without SLI? My motherboard doesn't support it.

 

3 hours ago, roarkr said:

I am using almost the same GPUs as you and I do not have your dramatic FPS drop.

Now I have one GTX 1070 and one GT 640, bith Nvidia cards.

You can see my setup here: 

http://www.flightsim4fun.com/b737-800-simulator.html

 

I do have reduced FPS, but it is more than good enough as the sim is smooth and without and stuttering.

 

 

 

 

The link says it is a GT 610, and here says it is a GT 640. Which one is it? I am asking because the GT 640 and the GTX 1070 use the same driver, while the GT 610 uses a different one. As I said, I suspect that the fact of the same driver being used for both GPUs could be the cause of the FPS drop. I'm not an expert in GPUs, so I'm not sure, but if you are using a GT 610, my suspicion may be correct. The GT 610 is also inferior to the 1030, consuming less resources from the system. However, it may be sufficient to run the instruments. Also, does the TH2GO help to increase the FPS? Since it allows to connect three monitors to just one port in the GPU, it doesn't have to handle three connections.  

Thanks!

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43 minutes ago, pedroaab said:

 

The link says it is a GT 610, and here says it is a GT 640. Which one is it? I am asking because the GT 640 and the GTX 1070 use the same driver, while the GT 610 uses a different one. As I said, I suspect that the fact of the same driver being used for both GPUs could be the cause of the FPS drop. I'm not an expert in GPUs, so I'm not sure, but if you are using a GT 610, my suspicion may be correct. The GT 610 is also inferior to the 1030, consuming less resources from the system. However, it may be sufficient to run the instruments. Also, does the TH2GO help to increase the FPS? Since it allows to connect three monitors to just one port in the GPU, it doesn't have to handle three connections.  

Thanks!

The image on my web site is an old one, Now I have a GT 640. But, there was no visible FPS changes going from GT 610 to GT 640. It was done to get the correct hardware connection for the monitor I use, I do not belive that it matters if the driver is used for one or two cards.

I do not know if TH2GO helps in any way, I have always used it in my setup. Without it I can't manage all instrument views.

 

What is important is to uninstall and reinstall Nvidia drivers after hardware changes and deleting P3D Shader folder and Prepar3d.cfg before starting up P3D

Edited by roarkr

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2 hours ago, roarkr said:

Thanks! Vsync was disabled in P3D, but not in NVidia Inspector. Disabling Vsync, NVidia In-Game Overlay and some Windows 10 settings helps to increase the FPS. Now I get about 27 (more and less stable), locked at 30. Without the instruments, I can get up to 50 FPS, so there is a loss, but it doesn't make a huge difference. I think it would be perfect if the instruments could run in the network with PMDG, but I couldn't find a way. The MIP displays in your cockpit are the PMDG ones?

Edited by pedroaab

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The MIP displays are all PMDG B737 undocked views. There is no way to network these views tat I know about.

 

You should also run main front view as Cockpit view without 2D panels( SHIFT1) 

Edited by roarkr

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Could the motherboard be a bottleneck in this case? Since there are two GPU's connected, could it reduce the performance to handle both?

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