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Fixed in 2022.1.X

Fixed in 2020.3.X, 2021.1.X, 2021.2.X



Found in







Issue ID




Performance in Game View is significantly impacted by Gfx.WaitForPresentOnGfxThread when a second monitor is connected



How to reproduce:
1. Create a new project using the default 3D template
2. Open the Profiler (Window->Analysis->Profiler)
3. Enter the Play Mode
4. Inspect the performance
5. Plug in a second monitor
6. Inspect the performance again

Expected result: Performance is not heavily affected when plugging in a second monitor
Actual result: Performance is heavily affected when plugging in a second monitor

Reproducible with: 2019.3.0b11, 2019.4.24f1, 2020.3.4f1, 2021.1.3f1, 2021.2.0a13
Not reproducible with: 2018.4.34f1, 2019.2.21f1, 2019.3.0b10

Tested on: macOS Catalina 10.15.7 with Radeon Pro 580 8 GB

  1. Resolution Note (fix version 2022.1):

    Fixed in: 2022.1.0a7

    Play Mode performance while using Metal would occasionally spike while a second monitor was attached - this was not visible before 2019.3 due to a Profiler issue. This frame present delay is fixed with the change to use CVDisplayLink with Metal on OSX to time presents, so that additional monitors do not affect performance.

  2. Resolution Note (fix version 2021.2):

    Fixed in: 2021.2.0b13

  3. Resolution Note (fix version 2021.1):

    Fixed in: 2021.1.22f1

  4. Resolution Note (fix version 2020.3):

    Fixed in: 2020.3.19f1

Comments (9)

  1. Ijin

    Oct 25, 2021 11:19

    With 2020.3.19f1 update it broke editor performance on single-monitor setups. Tested on Mac mini (2018), Big Sur and iMac (Late 2014), Big Sur.

  2. mellofelipe

    Sep 21, 2021 10:16

    Hi, I was the one that reported the bug. Is there any plan to do a fix for 2019 LTS as well?

  3. JohnnyFactor

    Aug 17, 2021 22:32

    I found this too but only when the Unity window was maximized to fill a monitor or crossed the boundary between the two monitors.

  4. justdizzy

    Jun 25, 2021 02:10

    [Unity 2020.3.8 & x.12] I just ran in to this, and in trying to find the issue, I stumbled upon that the FPS was matching my 2nd monitor's refresh rate, so I think that somehow the Editor is getting VSync locked regardless of settings?

  5. Beatriceol

    Jun 22, 2021 08:01

    When I click the mouse to switch focus, there may be a frame rate drop between Unity and the desktop or other applications. I don't know if it's the same problem as this.

  6. MeadowGames

    May 19, 2021 02:20

    I am also having this issue. On windows 10 PC. GTX 1050 16GB ram. You can easily reproduce the bug in 2018.4.26f1 and 2020.3.4f1. Major FPS drop with a second monitor. I've been driving myself crazy trying to fix this without dev support.

  7. JeffG

    May 07, 2021 18:07

    I went from 2020.1.17 ~60fps in Editor with 2 screens. Running 2020.3.5 now getting ~28 fps in Editor. Builds seem to be fine (back up to 60+)

  8. loten

    Apr 17, 2021 11:00

    Does this affect builds as well?

  9. oliviaark765

    Apr 12, 2021 11:57

    The same things happened to me when I was working for and Did the same thing as you mentioned above It is the best possible solution for improving the response and performance

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