# Select which GPU to use when starting ParaView
**URL:** https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605
**Category:** ParaView Support
**Tags:** opengl
**Created:** [February 19, 2020, 3:29pm UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605 "2020-02-19T15:29:50Z")
**Posts on this page:** 13
**Page:** 1
### Author:  [@ma-sadeghi](https://discourse.paraview.org/u/ma-sadeghi)
#### Post date: [February 19, 2020, 3:29pm UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/1 "2020-02-19T15:29:51Z")
Hello,
I have a workstation with two dissimilar GPUs. I only have one display, so expectedly, only one of the GPUs (GPU-1) is connected to my display. When I open ParaView -\> About, I see that ParaView only recognizes GPU-1.
Here’s my question: is there a way to tell ParaView to use the other GPU, i.e. GPU-2? (which is, by the way, not connected to my display)
Many thanks,
Amin
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [February 20, 2020, 2:11am UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/2 "2020-02-20T02:11:44Z")
Which OS ?
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### Author:  [@ma-sadeghi](https://discourse.paraview.org/u/ma-sadeghi)
#### Post date: [February 20, 2020, 2:33am UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/3 "2020-02-20T02:33:52Z")
Ubuntu
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [February 20, 2020, 2:55am UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/4 "2020-02-20T02:55:57Z")
Is this two actual GPUs or a chipset and a GPU (optimus laptop) ?
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### Author:  [@ma-sadeghi](https://discourse.paraview.org/u/ma-sadeghi)
#### Post date: [February 20, 2020, 3:01am UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/5 "2020-02-20T03:01:03Z")
Two actual GPUs: Quadro P400 which is connected to the monitor and RTX 8000
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [February 20, 2020, 3:02am UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/6 "2020-02-20T03:02:17Z")
Did you setup Xorg with the two cards ?
What is the output of `xrandr` ?
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### Author:  [@ma-sadeghi](https://discourse.paraview.org/u/ma-sadeghi)
#### Post date: [February 20, 2020, 3:38am UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/7 "2020-02-20T03:38:42Z")
I’m not sure, here’s the output of `xrandr`:
```auto
Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767
DP-0 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
DP-2 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 475mm x 267mm
1920x1080 60.00*+
1280x1024 75.02 60.02
1152x864 75.00
1024x768 75.03 60.00
800x600 75.00 60.32
640x480 75.00 59.94
DP-3 disconnected (normal left inverted right x axis y axis)
DP-4 disconnected (normal left inverted right x axis y axis)
DP-5 disconnected (normal left inverted right x axis y axis)
```
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [February 20, 2020, 3:51am UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/8 "2020-02-20T03:51:41Z")
You need to configure both screen as explained here :
[https://wiki.archlinux.org/index.php/Multihead#Separate\_screens](https://wiki.archlinux.org/index.php/Multihead#Separate_screens)
You have a fonctionnal example here :
[https://bbs.archlinux.org/viewtopic.php?id=175130](https://bbs.archlinux.org/viewtopic.php?id=175130)
This is not related to ParaView though. Once you have configured both screen and have multiple display, you will be able to use the secondary GPU for rendering within ParaView.
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### Author:  [@ma-sadeghi](https://discourse.paraview.org/u/ma-sadeghi)
#### Post date: [February 20, 2020, 6:36pm UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/9 "2020-02-20T18:36:58Z")
Thank you for your thorough response. Just to make sure, in order for ParaView to be able to use a GPU for rendering, that GPU must be connected to a physical monitor, is that correct?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [February 21, 2020, 2:55am UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/10 "2020-02-21T02:55:00Z")
I’m not entirely sure, as this is more in the domain of Xorg.
ParaView needs a valid DISPLAY id to be able to render to it using OpenGL.
>
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### Author:  [@lhofmann](https://discourse.paraview.org/u/lhofmann)
#### Post date: [February 21, 2020, 9:56am UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/11 "2020-02-21T09:56:35Z")
You could trick paraview into using the second GPU for rendering while still displaying the GUI using the first GPU, by building a headless pvserver with EGL support.
Then you can start the EGL pvserver locally on the workstation and specify the second GPU for rendering (`pvserver --egl-device-index=1`).
Finally, connect to it from your paraview GUI, that is displayed using the first GPU, and configure it to use remote rendering only (Remote Render Threshold 0).
I just tested this on my workstation, and it seems to work.
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### Author:  [@ltetrel](https://discourse.paraview.org/u/ltetrel)
#### Post date: [June 28, 2024, 7:59am UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/12 "2024-06-28T07:59:11Z")
I was hitting a similar issue with a laptop /w iGPU + NVIDIA dGPU, paraview would use my iGPU for rendering by default.
Make sure you have installed the NVIDIA (dkms) driver ([check here for ubuntu](https://www.cyberciti.biz/faq/ubuntu-linux-install-nvidia-driver-latest-proprietary-driver/)), and that [PRIME Render Offload](https://download.nvidia.com/XFree86/Linux-x86_64/435.17/README/primerenderoffload.html) is available.
You can then launch paraview with the following env variables:
```sh
__NV_PRIME_RENDER_OFFLOAD=1__ GLX_VENDOR_LIBRARY_NAME=nvidia paraview
```
You can create a wrapper script for paraview, or an alias.
This command should work for other graphic application as well.
Credits to our intern @Tom.Clabault for the cmd line.
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### Author:  [@Gatien\_Ferret](https://discourse.paraview.org/u/Gatien_Ferret)
#### Post date: [June 28, 2024, 8:31am UTC](https://discourse.paraview.org/t/select-which-gpu-to-use-when-starting-paraview/3605/13 "2024-06-28T08:31:34Z")
In case anyone searches for it on Windows and lands on this page.
The solution may be found on this [discourse page](https://discourse.paraview.org/t/running-on-gpu-from-windows/9339)