gfx.waitforPresent strikes again...I guess.

[abdo400]

So I am making a simple RTS for mobile - it is in 3D - and my code is well optimized but I always see in my profiler that it lags because of gfx.waitforPresent. I did some research and about its thread but and i concluded that I can’t really do something about it? Am I right about this?
If I am, should I move the project and assetws to 2D now, as this may reduces its effect?
I am aiming for high troop number in the battle scene, what should be done here?

[Ryiah]

@abdo400

I did some research and about its thread but and i concluded that I can’t really do something about it? Am I right about this?

Basically GFX.WaitForPresent is the period of time that the graphics card is waiting for the vertical refresh (also known as “Vsync”) to take place. This normally occurs every 16.6ms (though it depends on the monitor the user has). If the entire game is able to run in a period of 5ms, you still have to wait for the remaining 11.6ms that it takes for the display to be ready for another refresh.

If you need more details there is a comment on the Oculus forums with a more detailed explanation.

https://forums.oculus.com/developer/discussion/comment/260638/#Comment_260638

@abdo400

I am aiming for high troop number in the battle scene, what should be done here?

Absolutely nothing. The more complex your game becomes, the lower the number will be in the profiler. Just treat it the same as you treat the “System Idle Process” in Windows. It’s simply another way to see how idle the CPU is.

[ADNCG]

From what I read, it means the CPU is waiting for the GPU. Check the GPU stats.

Edit : Welp, treacherous forums didn’t tell me someone answered before me!

[Peter77]

@Ryiah

Basically GFX.WaitForPresent is the period of time that the graphics card is waiting

Here is a quote from UT staff to the question what “Gfx.WaitForPresent” means. It’s copied from https://forum.unity3d.com/threads/gfx-waitforpresent.211166/page-2#post-1726966

@ElvisAlistar

"A better name would be something like “waiting for renderer to catch up.”

It means that the main thread is waiting for the last frame to finish rendering, either on the render thread and GPU. Typically the GPU is the bottleneck, either because of Vsync or drawing too much stuff. It could also be submitting the frame to D3D/OpenGL that’s taking long.

The actual dependency is that the main thread waits for the render thread’s last frame, which waits for the GPU’s last frame. It could be either of those blocking the main thread. You have to find out what the cause is experimentally by disabling Vsync, rendering to a low resolution using simple shaders etc."

[Ryiah]

@Peter77

Here is a quote from UT staff to the question what “Gfx.WaitForPresent” means. It’s copied from https://forum.unity3d.com/threads/gfx-waitforpresent.211166/page-2#post-1726966

It’s only waiting for the renderer to catch up if you’re getting less than 60Hz (or whichever refresh rate your monitor is). The comment from the Oculus forum touches on that aspect. My understanding of the OP was that they hadn’t reached that point yet.

[EternalAmbiguity]

Just so you’re aware, you can “turn it off” by turning off VSync. You can turn off VSync in the quality settings for your project. Also keep in mind however that you may have other software running on your PC (such as RivaTuner) which limits applications to 60 FPS.

As long as VSync is unlocked, you won’t see that element in the profiler, and in the “stats” for a running game you’ll see frames per second higher than 60 (likely in the hundreds, maybe thousands).

[Peter77]

@EternalAmbiguity

Just so you’re aware, you can “turn it off” by turning off VSync.

He wrote he is targeting mobile. I’m not aware that you can turn off v-sync on mobile.

[abdo400]

Thank you for your replies.

So changing the models to animated 2D sprites won’t add much?

[EternalAmbiguity]

@Peter77

He wrote he is targeting mobile. I’m not aware that you can turn off v-sync on mobile.

Ah, didn’t see that. My bad.

@abdo400

Thank you for your replies.

So changing the models to animated 2D sprites won’t add much?

It may, but basically it’s not something you need to worry about. It’s already been said but “waitforPresent” basically means the game’s already running as fast as it can on your current hardware (simplifying a bit).

You can look at all of the other things in the profiler, and take note of if they decrease in their amount of time (shown as ms, milliseconds) when you make the change, but it’s not really something you need to worry about until the gfx.waitforPresent amount is getting pretty low.