Jump to content
Sign in to follow this  
pedroaab

Second GPU to detach displays - not expected behavior

Recommended Posts

Hello,

This is my first topic in the forum. I run Prepar3D v3 in my computer (Windows 10), usually with PMDG 737NGX and 4 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 30 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. As far as I know, the GT 1030 is much better than the integrated graphics, so why is this happening? I suspect the reason behind this is the fact that both video cards use the same driver, so the system is using just one GPU to process data. This is not the case of Intel 630. Is there a way to use the GT 1030 for detached displays in its real potential? If the driver being the same is really the problem, changing the NVidia 1030 to a Radeon would deliver better performance?

Thanks!

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

16 GB of RAM at 2133 MHz DDR4

Share this post


Link to post
On 5/3/2018 at 1:32 PM, pedroaab said:

Hello,

This is my first topic in the forum. I run Prepar3D v3 in my computer (Windows 10), usually with PMDG 737NGX and 4 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 30 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. As far as I know, the GT 1030 is much better than the integrated graphics, so why is this happening? I suspect the reason behind this is the fact that both video cards use the same driver, so the system is using just one GPU to process data. This is not the case of Intel 630. Is there a way to use the GT 1030 for detached displays in its real potential? If the driver being the same is really the problem, changing the NVidia 1030 to a Radeon would deliver better performance?

Thanks!

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

16 GB of RAM at 2133 MHz DDR4

Maybe it's a memory issue?
The 2GB of the 1030 sound way to low to run three monitors.
How much memory does the integrated video have access to?

gb.


YSSY. Win 10, 6700K@4.8, Corsair H115i Cooler, RTX 4070Ti, 32GB G.Skill Trident Z F4-3200, Samsung 960 EVO M.2 256GB, ASUS Maximus VIII Ranger, Corsair HX850i 850W, Thermaltake Core X31 Case, Samsung 4K 65" TV.

Share this post


Link to post

The reason for me was locking frames from an external program like inspector. Maybe this is the problem you are experiencing.

Shez


Shez Ansari

Windows 11; CPU: Intel Core i7-8700K; GPU: EVGA GEFORCE GTX 1080Ti 11GB; MB: Gigabyte Z370 AORUS Gaming 5; RAM: 16GB; HD: Samsung 960 Pro 512GB SSD, Samsung 850 Pro 256GB SSD; Display: ASUS 4K 28", Asus UHD 26"

Share this post


Link to post

Mounting 2 GPU`s on the motherboard will half the bandwidth for each GPU, AKA one GPU slot PCIEX16/8 one GPU 16 lanes, 2 GPU`s 2X8= 8 lanes each. 

And you may find like ram if two stick of ram have a different clock speed the system will default to the slowest ram speed.

Edited by rjfry

 

Raymond Fry.

PMDG_Banner_747_Enthusiast.jpg

Share this post


Link to post
On 5/4/2018 at 3:28 AM, gboz said:

Maybe it's a memory issue?
The 2GB of the 1030 sound way to low to run three monitors.
How much memory does the integrated video have access to?

gb.

You are right, it really seems too low, but the integrated video has access to 1GB only.

 

19 hours ago, ShezA said:

The reason for me was locking frames from an external program like inspector. Maybe this is the problem you are experiencing.

Shez

The frames were locked at 30 FPS at NVidia Inspector. I have tried to change the values but no success.

Share this post


Link to post
17 hours ago, rjfry said:

Mounting 2 GPU`s on the motherboard will half the bandwidth for each GPU, AKA one GPU slot PCIEX16/8 one GPU 16 lanes, 2 GPU`s 2X8= 8 lanes each. 

And you may find like ram if two stick of ram have a different clock speed the system will default to the slowest ram speed.

Thanks for your answer!

That makes sense for the 1030... right now all my displays are connected to the 1070 and onboard, but the 1030 is connected to the motherboard and working in the system. The Intel Graphics doesn't seem to limit the GTX 1070 (is that makes sense?). In fact, when I drag the textures screen to a monitor conneted to onboard graphics, it can't handle the load. So if I remove the 1030 and mantain the onboard active, would the system work in full capacity? 

I think the GTX 1070 should be capable to handle more displays, but if connect the displays in it, I have a huge FPS drop. The FPS also drops if I drag the detached displays to the 1070 monitor alone, which I think it should not drop, since the workload in this GPU is lower than 60% and the processor is not overcharged. So is something wrong with my software setup? 

If I change the NVidia 1030 to a Radeon, using a different driver, would the system limit to the lowest clock speed?  

Share this post


Link to post
28 minutes ago, pedroaab said:

Thanks for your reply. You are right, it really seems too low, but the integrated video has access to 1GB only.

 

Thanks for your reply. The frames were locked at 30 FPS at NVidia Inspector. I have tried to change the values but no success.

 

Share this post


Link to post
3 hours ago, pedroaab said:

 

What I meant was to unlock the frames from inspector and not use it, and just go unlimited. That is the only way I got it to not dip FPS. If you need the inspector then you will see the dip. I am not sure why this happens...

Shez

Edited by ShezA

Shez Ansari

Windows 11; CPU: Intel Core i7-8700K; GPU: EVGA GEFORCE GTX 1080Ti 11GB; MB: Gigabyte Z370 AORUS Gaming 5; RAM: 16GB; HD: Samsung 960 Pro 512GB SSD, Samsung 850 Pro 256GB SSD; Display: ASUS 4K 28", Asus UHD 26"

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
×
×
  • Create New...