Windowed mode vs Fullscreen fps issue (Laptop with external monitor)

[MagicMight]

So this problem has persisted for ages and while not detrimental, it has been quite annoying. I really hope that the experienced posters here will have some idea of what I might have missed.

Laptop specs
Lenovo Legion Y520
i7 7700hq
gtx 1060 max-q
256 SSD + 1TB 7200 HDD
16 GB dual channel ram 2400 mhz
Windows 10 1903

The issue occurs when I have the laptop connected to an external monitor (a simple 1080p 60hz one) through an HDMI cable and use that exclusively('only use second monitor' option). Whenever I run a game on windowed mode, the game's fps is stuck to 50-54 (and 40-45 on other games) and the frametimes jump up and down like crazy. That, of course makes the game feel incredibly choppy. Even if I disable vsync, the fps does not change.
If I go full screen, the issue immediately goes away. Smooth 60 fps(with vsync) and steady frametimes. If I am using the laptop's screen instead of an external one, this issue is non-existent.

I have reproduced the issue with all the games I tried: Witcher 3, World of warcraft, Hitman 2, Human Fall flat and I assume that this will be the case with any other game too. Heck I even ran the vsync, fps and refresh rate browser test on testufo.com and even there, I get the same 50-54 fps thing.

Here are some screenshots of it happening on two games:

https://imgur.com/a/RSXnbYd

I have made sure that GPU1 is the nvidia gpu on those pictures.

If you take note of the first and third picture, you will see that windowed mode behaves exactly like fullscreen when the latter was out of focus. (But I don't have any other programs open or stealing focus when on windowed mode...)

This gets fixed if I restart the pc and immediately launch a game on windowed mode. Steady 60 fps then for as long as I play. The issue also gets fixed 'sometimes' (actually rarely) if I remove and reinsert the hdmi cable, or if I switch from 'use only screen 2' to 'duplicate these displays' (where the issue never occurs) and back to 'use only screen 2'.


I can't test if this occurs in safe mode since the nvidia gpu drivers do not get loaded there and I can't use an external screen while on safe mode anyway.

Things I have tried:

-Checked the temps and they are not the issue.

-Checked gpu frequency and despite the difference on those screenshots it is usually the same in both fullscreen and windowed modes (gpu usage is always lower on windowed though).

-Tried two different HDMI cables.

-Tried another external monitor,same issue.

-DDU of both intel and nvidia graphics drivers in safe mode, and re-installation of both latest drivers and earlier versions.

-Made sure all the nvidia settings (both game-specific and global) were set to high performance and preferred gpu is the gtx card.

-High performance windows plan.

-Disabled windows game bar and Lenovo's game boosting software.

-Ran malwarebytes and windows defender scans (Yep I am getting desperate).

Things I haven't tried and would really like to avoid:

-Bios update.
-Windows re-installation.

[Komrade]

Just run your games fullscreen, most games require fullscreen to be properly focused and running at max performance. What you’re describing is normal.

[_I_]

if its a single or cloned display use full screen instead of windowed/full

[MagicMight]

Thank you for your suggestions to run the games in full screen but this does not actually solve the issue. It just hides it.

I don't really mind running my games in full screen (in fact I do so most of the time), but in some of them such as WoW it is much more handy to have a windowed instance of the game running since I usually need to have other app windows open and easily reachable. I can of course run full screen and alt tab every time I need to use something else, but that is actually the inconvenience that was mentioned in the OP and the reason I want to fix this.

I do not need to run most of my other games in windowed mode, however I tested them and listed them here to make sure myself and convey to you that this is not a game-specific issue but rather a Windows or driver-related problem.

Originally posted by christmaS:

Just run your games fullscreen, most games require fullscreen to be properly focused and running at max performance. What you’re describing is normal.

I agree that games are meant to run better in exclusive full screen. However, I can run all these games perfectly in windowed when using the laptop's own screen (same resolution and refresh rate), and it works fine on the external monitor as well right after a restart, as mentioned in the OP. If what you were saying was the case here, would that problem not be universally consistent?

[trunks.]

maneiro legal
to nem ai krai

[Crashed]

Full screen can have higher FPS and/or lower latency because it bypasses the desktop compositor thus meaning less steps for the GPU to bring the game screen from VRAM to your monitor.

[MagicMight]

Originally posted by Crashed:

Full screen can have higher FPS and/or lower latency because it bypasses the desktop compositor thus meaning less steps for the GPU to bring the game screen from VRAM to your monitor.

I appreciate the explanation of why windowed can in general perform worse than full screen but I think I'll quote my answer to the post above:

Originally posted by MagicMight:

However, I can run all these games perfectly in windowed when using the laptop's own screen (same resolution and refresh rate), and it works fine on the external monitor as well right after a restart, as mentioned in the OP. If what you were saying was the case here, would that problem not be universally consistent?

Besides, would you claim that even a game like Warcraft that can easily run 60 fps on toaster-grade hardware would also fall within your argument? (It doesn't by the way since it works fine on windowed on other computers with way inferior specs).

[hawkeye]

It's years since I have done any coding but I am almost certain that the different window modes don't work the same way. If I remember correctly there were at least 3 modes - windows, windows borderless and full screen. As Crashed says full screen was faster because the game wasn't running in a Windows "window" (the object with borders, scroll bars, headers, min/max buttons, font handling etc).

[Crashed]

Originally posted by hawkeye:

It's years since I have done any coding but I am almost certain that the different window modes don't work the same way. If I remember correctly there were at least 3 modes - windows, windows borderless and full screen. As Crashed says full screen was faster because the game wasn't running in a Windows "window" (the object with borders, scroll bars, headers, min/max buttons, font handling etc).

Windowed borderless is simply windowed mode stretched to fill the screen. Fullscreen still has a window in order to obscure anything behind it from drawing over the screen, but tells the display driver to instead of sending the graphics to the window's Device Context to send it straight to the framebuffer.

In Windows Vista through early versions of 10 DirectX would turn off the desktop composition completely however now it stays in standby to allow overlays to display (what's known as Fullscreen Optimization) so it runs in a sort of borderless window mode nowadays. OpenGL and Vulkan can still run in exclusive mode on Windows.