FPS increase in games after ALT+TAB

Discussion in 'Videocards - NVIDIA GeForce Drivers Section' started by klunka, Jul 24, 2020.

  1. klunka

    klunka Member

    Messages:
    32
    Likes Received:
    6
    GPU:
    1080ti / 11gb
    Hi, first post and wanted to say thank you for all the great info on this site, very awesome!

    I have a minor issue right now, not even, more a curiosity. I tested this in multiple games and with different drivers:
    For example in Apex legends, on a random spot inside shooting range I will get 260fps stable. I tab out of the game and back in, suddenly I get 290fps. This effect lasts 10-20 seconds after that I return to baseline 260fps. I can repeat and replicate this as often as I want and on any spot in the shooting range, doesn't matter.

    I searched and found this very old thread
    https://forums.guru3d.com/threads/what-is-alt-tab-problem-and-what-does-it-do.240317/

    Apparantly back then there was a driver issue with Vram management, if I read that right. I checked my memory usage with MSI afterburner but it's constant and at around 1300 mb.

    My specs:
    1080ti
    Xeon E3-1230
    16gb DDR3
    Windows 10, 1909
    Ingame: Everything ultra low, no vsync, no fps cap etc.; turned off full screen optimizations.

    Any ideas what's happening or any tests I could do? If you could try this out and tell me if you get the same effect(which game doesn't matter) that would be awesome!
     
    BlindBison likes this.
  2. Mda400

    Mda400 Master Guru

    Messages:
    927
    Likes Received:
    112
    GPU:
    3060Ti 2055/16.2Ghz
    I've only noticed something similar when running Unigine Valley benchmark in DX11, but has been that way as long as I can remember using Windows 10 (2015).

    My first guess would be something related to the graphics API or Nvidia's driver in relation to the programs it happens with.
     
  3. klunka

    klunka Member

    Messages:
    32
    Likes Received:
    6
    GPU:
    1080ti / 11gb
    Thanks for sharing!
    It's happening at least in both DX11 and vulkan games for me.
     
  4. evgenim

    evgenim Master Guru

    Messages:
    236
    Likes Received:
    17
    GPU:
    RTX 2060 OC
    Watching this phenomenon since Far Cry 3.
     

  5. klunka

    klunka Member

    Messages:
    32
    Likes Received:
    6
    GPU:
    1080ti / 11gb
    Oh dang, decent game though!
     
  6. jbscotchman

    jbscotchman Ancient Guru

    Messages:
    5,777
    Likes Received:
    4,571
    GPU:
    MSI 1660 Ti Ventus
    I had the same issue in GTA Online. When I get in the game I'd be locked at 48fps, but with a quick alt-tab I shoot up into the 80's. I also had the same problem in A Plague Tale Innocence recently, but switching from HDMI to Display Port fixed that issue. As for GTAO, who knows. I'm done with that garbage and it's uninstalled.
     
  7. klunka

    klunka Member

    Messages:
    32
    Likes Received:
    6
    GPU:
    1080ti / 11gb
    @jbscotchman
    Are you saying this doesn't happen in your other games? I am using Display Port fwiw

    Man I tried for a good hour again to find out what's happening. I looked if any service or process starts/ends, -nothing. Checked if any background process is changing CPU usage with process explorer -nothing.

    What could possibly change in a 10 second window after tabbing into a fullscreen application?
    -No process starts or ends
    -No process alters CPU usage in any meaningful way
    -What else?

    Is there any monitoring tools for GPU, something like afterburner, but more in depht?
    Edit: Another question I had in mind to ask. When you tab out of a game, does the Vram get cleared?
     
  8. kurtextrem

    kurtextrem Master Guru

    Messages:
    244
    Likes Received:
    27
    GPU:
    NVIDIA GeForce GTX 970
    I'd say it's a priority boost most likely (windows scheduling). Can you check your win32seperation value?
     
  9. jbscotchman

    jbscotchman Ancient Guru

    Messages:
    5,777
    Likes Received:
    4,571
    GPU:
    MSI 1660 Ti Ventus
    Yes. It's very bizarre I know.
     
  10. klunka

    klunka Member

    Messages:
    32
    Likes Received:
    6
    GPU:
    1080ti / 11gb
    My value is 2
     

  11. kurtextrem

    kurtextrem Master Guru

    Messages:
    244
    Likes Received:
    27
    GPU:
    NVIDIA GeForce GTX 970
    Set it to "background programs" and then "applications" again, that way it will set a different value which is in my experience better than the (installation) default.
     
  12. klunka

    klunka Member

    Messages:
    32
    Likes Received:
    6
    GPU:
    1080ti / 11gb
    Ahh thanks!
    For people wondering Win32PrioritySeperation changed to 26 hex in: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\PriorityControl

    Unfortunately it didn't resolve the problem.
    I tried with another game(can't change priority in apex) and set priority to real-time in taskmanager just to see if it would change anything, but nope...
    Also tried windowed mode -same effect.

    Still not sure if it's just me or everyone that is affected....from the games I tested the effect can be less pronounced based on which game you play (30+- fps in apex vs 10+- in hyperscape).
     
  13. jbscotchman

    jbscotchman Ancient Guru

    Messages:
    5,777
    Likes Received:
    4,571
    GPU:
    MSI 1660 Ti Ventus
    I would not start changing registry settings. That's just gonna give you more problems down the road.
     
  14. klunka

    klunka Member

    Messages:
    32
    Likes Received:
    6
    GPU:
    1080ti / 11gb
    Nah the windows setting option changed the key....
     
  15. Astyanax

    Astyanax Ancient Guru

    Messages:
    10,261
    Likes Received:
    3,678
    GPU:
    GTX 1080ti
    game engines unload stuff from memory on tab switching, if performance increases its only because things that were in memory are currently unloaded and not being checked for culling.
     
    cryohellinc likes this.

  16. klunka

    klunka Member

    Messages:
    32
    Likes Received:
    6
    GPU:
    1080ti / 11gb
    @Astyanax
    I bet you're right, though I know nothing about this stuff. Out of curiosity, what would happen if you programmed a game to unload the memory like that periodically every X seconds?
     
  17. octo

    octo New Member

    Messages:
    4
    Likes Received:
    1
    GPU:
    Xfire 5870's
  18. Blackfyre

    Blackfyre Maha Guru

    Messages:
    1,099
    Likes Received:
    89
    GPU:
    RTX 2070 Super
    Interesting thread, how long are you alt-tabbing out of the game?

    Just thinking out loud here
    , but it is possible that the video card is not sufficiently cooled (or has a low-quality cooler) whereby when alt-tabbing out, the temperature decreases significantly enough that when returning to the game you are entering back with higher core clock and memory speeds on the videocard, and thus a higher frame-rate. The GPU heats back quickly within 10 to 20 seconds and framerate drops to the regular level of your heated GPU.
     
    AsiJu and Cave Waverider like this.
  19. Cave Waverider

    Cave Waverider Maha Guru

    Messages:
    1,095
    Likes Received:
    124
    GPU:
    RTX 3090 ROG Strix
    That's the thought that came to my mind as well. It certainly seems plausible.
     
  20. klunka

    klunka Member

    Messages:
    32
    Likes Received:
    6
    GPU:
    1080ti / 11gb
    Nailed it! Don't know how I missed it, was using afterburner and didn't even think about temps....my processor is so old, I rarely get the GPU to max temp.
    Thanks man, what a relief :)
     
    AsiJu and Blackfyre like this.

Share This Page