Dual monitor extremely slow #96248

New Issue

HF · 2022-03-08T23:39:29+01:00

HF commented

2022-03-08 23:39:29 +01:00

System Information
Operating system: Windows-10
Graphics card: 2080s+2070s
32gb 3700x

Blender Version
Broken: version: 3.1.0 Release Candidate, branch: master, commit date: 2022-03-03 16:21, hash: 769ae5c866
worked: 2.83.19

Short description of error
setup: i have 4 monitor all plugged into the 2070s, when I'm working i use a 4k monitor for cycles rendered view and i do other stuff on a 2.5k monitor, the other monitors are HD which are not used by blender.

the problem is when i switch to the rendered view on the 4k monitor it will start to load render kernel for a long time, but i can render it on other monitors with no problem, (one time it loaded render kernel for 15 mins, for s simple scene like the one below)
after it loads render kernel, doing anything (like selecting, moving...) on the 2.5k monitor will cause the 4k monitor to go black, and load render kernel again for a long time (about 30 secs),
and it will also say other stuff other than loading render kernel, i have attached a previous report below showing exactly what other message it shows.

i remembered using the exact setup in a beta build of cyclesX, didnt have this issue. but maybe its file-related

i have also shrunk the render view to 1080 on the 4k monitor, it is smoother but it will still load the render kernel randomly

this is a previous report on a similar problem, (i later find out that the scene stats doesn't really matter)
https://developer.blender.org/T95561

it might relate to the dual graphics card problem I've been reporting

i also tried the same file in 2.83.19, load kernel instantly and have no problem at all when moving selecting, screen will not go black and load render kernel.

Exact steps for others to reproduce the error
use the rendered view on another screen (4k if possible)
this is the blend file{F12909854}

**System Information** Operating system: Windows-10 Graphics card: 2080s+2070s 32gb 3700x **Blender Version** Broken: version: 3.1.0 Release Candidate, branch: master, commit date: 2022-03-03 16:21, hash: `769ae5c866` worked: 2.83.19 **Short description of error** setup: i have 4 monitor all plugged into the 2070s, when I'm working i use a 4k monitor for cycles rendered view and i do other stuff on a 2.5k monitor, the other monitors are HD which are not used by blender. the problem is when i switch to the rendered view on the 4k monitor it will start to load render kernel for a long time, but i can render it on other monitors with no problem, (one time it loaded render kernel for 15 mins, for s simple scene like the one below) after it loads render kernel, doing anything (like selecting, moving...) on the 2.5k monitor will cause the 4k monitor to go black, and load render kernel again for a long time (about 30 secs), and it will also say other stuff other than loading render kernel, i have attached a previous report below showing exactly what other message it shows. i remembered using the exact setup in a beta build of cyclesX, didnt have this issue. but maybe its file-related i have also shrunk the render view to 1080 on the 4k monitor, it is smoother but it will still load the render kernel randomly this is a previous report on a similar problem, (i later find out that the scene stats doesn't really matter) https://developer.blender.org/T95561 it might relate to the dual graphics card problem I've been reporting i also tried the same file in 2.83.19, load kernel instantly and have no problem at all when moving selecting, screen will not go black and load render kernel. **Exact steps for others to reproduce the error** use the rendered view on another screen (4k if possible) this is the blend file{[F12909854](https://archive.blender.org/developer/F12909854/1.blend)}

HF commented

2022-03-08 23:39:29 +01:00

Added subscriber: @Hongyu

blender-admin commented

2022-03-08 23:39:29 +01:00

#101302 was marked as duplicate of this issue

Pratik Borhade commented

2022-03-09 05:26:45 +01:00

Added subscriber: @PratikPB2123

Omar Emara commented

2022-06-24 09:16:25 +02:00

Added subscriber: @OmarEmaraDev

Omar Emara commented

2022-06-24 09:16:25 +02:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Omar Emara commented

2022-06-24 09:16:25 +02:00

Sorry for leaving this unattended for that long.

You say all monitors are plugged into the 2070, does that mean you are rendering with your 2080 or both? Does this happen with both OptiX and CUDA?

i have attached a previous report below showing exactly what other message it shows.

I can't see that attachment, unless you mean it is the messages in the other report you linked, in which case can you attach the logs as described below?

Please open Blender's installation directory and double click on the blender_debug_gpu.cmd. This will start Blender in debug mode and create log files. Try to reproduce the error again. Once it crashes or you close Blender manually the Windows Explorer should open and show you up to two files, a debug log and the system information. Add them to your bug report by clicking on the upload button as shown in the screenshot below or via drag and drop. Please also upload the crash log located in C:\Users\[your username]\AppData\Local\Temp\[project name].crash.txt (or simply type %TEMP% into the path bar of the Windows Explorer).

Sorry for leaving this unattended for that long. You say all monitors are plugged into the 2070, does that mean you are rendering with your 2080 or both? Does this happen with both OptiX and CUDA? > i have attached a previous report below showing exactly what other message it shows. I can't see that attachment, unless you mean it is the messages in the other report you linked, in which case can you attach the logs as described below? Please open Blender's installation directory and double click on the `blender_debug_gpu.cmd`. This will start Blender in debug mode and create log files. Try to reproduce the error again. Once it crashes or you close Blender manually the Windows Explorer should open and show you up to two files, a debug log and the system information. Add them to your bug report by clicking on the upload button as shown in the screenshot below or via drag and drop. Please also upload the crash log located in `C:\Users\[your username]\AppData\Local\Temp\[project name].crash.txt` (or simply type `%TEMP%` into the path bar of the Windows Explorer).![2019_12_04_upload_icon_developer_blender_org.png](https://archive.blender.org/developer/F8190038/2019_12_04_upload_icon_developer_blender_org.png)

HF commented

2022-07-05 04:52:21 +02:00

yes i meant the other report i linked

i will run debug ans sent it here later

yes i meant the other report i linked i will run debug ans sent it here later

Omar Emara commented

2022-08-04 13:23:12 +02:00

Did you gave the time to look into this?

HF commented

2022-08-04 20:01:44 +02:00

i will look into it this weekend

HF commented

2022-08-10 23:14:17 +02:00

i opened the file in 3.2.2, at first it was able to render,
i have the main screen as navigation and a 4k screen as display as described above,

as soon as i start doing things on the main screen, it started to load kernel for a long time,
and when i do anything on the main screen after, the kernel will reload all over again. then i just closed blender. didn't wait for it to load, but it didn't crash.

blender_system_info.txt

blender_debug_output.txt

i opened the file in 3.2.2, at first it was able to render, i have the main screen as navigation and a 4k screen as display as described above, as soon as i start doing things on the main screen, it started to load kernel for a long time, and when i do anything on the main screen after, the kernel will reload all over again. then i just closed blender. didn't wait for it to load, but it didn't crash. [blender_system_info.txt](https://archive.blender.org/developer/F13358675/blender_system_info.txt) [blender_debug_output.txt](https://archive.blender.org/developer/F13358676/blender_debug_output.txt)

HF commented

2022-08-11 01:12:46 +02:00

i tried again in the newest 3.3 beta, same problem.

this time i decided to record the entire process.

it first started to load kernel, but it wasn't the first time opening blender 3.3, after that, i was simply selecting an object and it when back to loading kernel.blender bug.mov

blender_system_info.txt

blender_debug_output.txt

i tried again in the newest 3.3 beta, same problem. this time i decided to record the entire process. it first started to load kernel, but it wasn't the first time opening blender 3.3, after that, i was simply selecting an object and it when back to loading kernel.[blender bug.mov](https://archive.blender.org/developer/F13358814/blender_bug.mov) [blender_system_info.txt](https://archive.blender.org/developer/F13358732/blender_system_info.txt) [blender_debug_output.txt](https://archive.blender.org/developer/F13358733/blender_debug_output.txt)

Omar Emara commented

2022-08-11 07:42:44 +02:00

Changed status from 'Needs User Info' to: 'Needs Triage'

Gianna commented

2022-08-12 14:26:35 +02:00

Added subscriber: @gianna-thompson

Gianna commented

2022-08-12 14:26:35 +02:00

I have exactly the same problem.
I run blender from my laptop ( 32GB RAM, rtx 2070, i9-9880H) and I have connected a second Monitor with HDMI cable.

If I keep blender open just on the Laptop screen, everything goes just fine. As soon as I split the qidwos between the two screens, to be precise the view port on the laptop, shader editor, properties and so on on the other one, the render preview on the viewport gets insanely slow.
It is enough just to select another geometry on the screen to make everything disappear, run a solid 30 seconds of "light update" "scene update" "kernel calculation" and all that jazz.

I'm not able to get around the issue by myself...

Interestingly, Cycles is much more effected than EEVEE on this particular issue.

I have exactly the same problem. I run blender from my laptop ( 32GB RAM, rtx 2070, i9-9880H) and I have connected a second Monitor with HDMI cable. If I keep blender open just on the Laptop screen, everything goes just fine. As soon as I split the qidwos between the two screens, to be precise the view port on the laptop, shader editor, properties and so on on the other one, the render preview on the viewport gets insanely slow. It is enough just to select another geometry on the screen to make everything disappear, run a solid 30 seconds of "light update" "scene update" "kernel calculation" and all that jazz. I'm not able to get around the issue by myself... Interestingly, Cycles is much more effected than EEVEE on this particular issue.

Omar Emara commented

2022-09-29 14:17:02 +02:00

Added subscribers: @binadhed, @mano-wii

Charlie Hsia commented

2022-11-18 09:49:31 +01:00

Added subscriber: @chhs

HF commented

2023-02-25 18:41:24 +01:00

i found out this will only happen when i set the ui scale higher like above 1.2

Harley Acheson commented

2023-02-25 21:05:28 +01:00

Are all your monitors set to the same UI scale? As in not the Interface scale within Blender but the setting within the operating system? Settings / System / Display / Scale and Layout.

There could be some added slowdown (that I haven't personally noticed) when these vary between monitors, as we need to draw with one scale on one monitor then at another on the next, many times per second.

One example is the type of icons we use for the Tools (shown on the left side of the 3D View). These are rasterized from vectors (made into bitmaps) and are therefore cached, but just for a single size. So the caching of this rasterization would not be useful with multiple monitors varying in scale. There might be other issue like this.

So do you experience this same slowdown if you set the scale the same on all monitors? Do you experience this slowdown if all windows just contain something simple like a Text Editor or does it only happen when you have some particular arrangement of multiple editors?

Are all your monitors set to the same UI scale? As in not the Interface scale within Blender but the setting within the operating system? Settings / System / Display / Scale and Layout. There could be some added slowdown (that I haven't personally noticed) when these vary between monitors, as we need to draw with one scale on one monitor then at another on the next, many times per second. One example is the type of icons we use for the Tools (shown on the left side of the 3D View). These are rasterized from vectors (made into bitmaps) and are therefore cached, but just for a single size. So the caching of this rasterization would not be useful with multiple monitors varying in scale. There might be other issue like this. So do you experience this same slowdown if you set the scale the same on all monitors? Do you experience this slowdown if all windows just contain something simple like a Text Editor or does it only happen when you have some particular arrangement of multiple editors?

Harley Acheson added

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Needs Triage

labels 2023-02-26 00:04:29 +01:00

Thomas Dinges commented

2023-05-12 15:44:35 +02:00

No activity for more than a week. As per the tracker policy we assume the issue is gone and can be closed.

Thanks again for the report. If the problem persists please open a new report with the required information.

No activity for more than a week. As per the tracker policy we assume the issue is gone and can be closed. Thanks again for the report. If the problem persists please open a new report with the required information.

Thomas Dinges closed this issue

2023-05-12 15:44:36 +02:00

Blender Bot added

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labels 2023-05-12 15:44:38 +02:00

HF commented

2023-08-15 05:57:21 +02:00

yes, i found out the problem only exist when desktop is set to different scale, i have one 4k one 2k monitor so they have to be set to different scale, the problem is appearing when blender ui scale is above 1.1

can is issue be reopened? or i have to create a new one?

yes, i found out the problem only exist when desktop is set to different scale, i have one 4k one 2k monitor so they have to be set to different scale, the problem is appearing when blender ui scale is above 1.1 can is issue be reopened? or i have to create a new one?

Gianna commented

2023-08-15 07:12:56 +02:00

Wow ok! This is actually also my case, my Monitor is on a different scale!!! Did you manage to solve it? *Hongyu Fu?

HF commented

2023-08-15 23:35:20 +02:00

@gianna-thompson if you set the blender ui scale to 1 it will solve it

Gianna commented

2023-08-16 07:07:15 +02:00

Thank you @Hongyu !!!

Thomas Dinges commented

2023-10-06 16:51:14 +02:00

Sorry for the late reply and thanks for providing more information.

@Harley Is that something you can test maybe? Or someone else from the dev team with two monitors with different resolutions.

Sorry for the late reply and thanks for providing more information. @Harley Is that something you can test maybe? Or someone else from the dev team with two monitors with different resolutions.

Thomas Dinges reopened this issue

2023-10-06 16:51:17 +02:00

Blender Bot added

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labels 2023-10-06 16:51:19 +02:00

Harley Acheson commented

2023-10-06 18:39:52 +02:00

I have three monitors and can test some of these issues, but I don't have any high-DPI monitors or any that support HDR. Basically they are all regular old monitors, each displaying 1920 x 1080. All plugged into a single RTX 4080.

When you have multiple windows open on monitors that differ in OS scale or DPI, Blender then has draw at one size on one window and a different size on the other. These calculations in between drawing are trivial and should not impact performance in itself. But what is being drawn and how could make a difference.

For example, if one monitor is high-definition (high DPI, like Retina) while the other is a regular definition monitor then you can have a situation where rendering on one monitor might take longer than another because the high-definition monitor has four times the pixels in the same space.

We also could have underlying problems to do with multiple monitors, known or unknown. For example if you have the same Node tree open on two monitors at once and they differ in scale then you won't be able to select properly on one. This is a current code limitation. And we have potential caching problems for the icons shown on the 3D Viewport toolbar when they are shown at different sizes on multiple windows.

But I suspect all the problems with this complaint are to do with one monitor being a much higher resolution than the others, so the rendered area is four times the number of pixels. The other potential complication is the setup of the original complaint shows two video cards - "2080s+2070s". This question was asked of them: "You say all monitors are plugged into the 2070, does that mean you are rendering with your 2080 or both? Does this happen with both OptiX and CUDA?" but that was not answered as far as I can tell.

But again, I don't have a 4K monitor or multiple adapters so I can't test this situation very well.

I have three monitors and can test some of these issues, but I don't have any high-DPI monitors or any that support HDR. Basically they are all regular old monitors, each displaying 1920 x 1080. All plugged into a single RTX 4080. When you have multiple windows open on monitors that differ in OS scale or DPI, Blender then has draw at one size on one window and a different size on the other. These calculations in between drawing are trivial and should not impact performance in itself. But **what** is being drawn and how could make a difference. For example, if one monitor is high-definition (high DPI, like Retina) while the other is a regular definition monitor then you can have a situation where rendering on one monitor might take longer than another because the high-definition monitor has four times the pixels in the same space. We also could have underlying problems to do with multiple monitors, known or unknown. For example if you have the same Node tree open on two monitors at once and they differ in scale then you won't be able to select properly on one. This is a current code limitation. And we have potential caching problems for the icons shown on the 3D Viewport toolbar when they are shown at different sizes on multiple windows. But I suspect all the problems with this complaint are to do with one monitor being a much higher resolution than the others, so the rendered area is four times the number of pixels. The other potential complication is the setup of the original complaint shows two video cards - "2080s+2070s". This question was asked of them: "You say all monitors are plugged into the 2070, does that mean you are rendering with your 2080 or both? Does this happen with both OptiX and CUDA?" but that was not answered as far as I can tell. But again, I don't have a 4K monitor or multiple adapters so I can't test this situation very well.

Pratik Borhade added

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labels 2023-10-09 11:21:10 +02:00

Pratik Borhade commented

2024-03-01 07:09:21 +01:00

@Hongyu hi, any updates?