Understanding performance on android

Hi

I'm using a;
Samsung Galaxy Tab 3 Tablet
- 1.2 Dual Core Processor
- 1 Gig RAM
- 1024 x 600 Screen Rez

Unity 5.0.0f4

I've created a scene with a cube sitting on a plane, both using a default texture. No skybox. Quality settings are at "Fast" with no shadows.

V Sync is set to "Don't Sync"

I'm running with the device connected to the profiler over wifi



What I see on the device is a fluctuation between 40 fps and around 62 fps.

Drawcalls are at "4"

The only CPU usage is the Graphics.PresentAndSync -> Device.Present which fluctuates at 16ms to 30ms and would seem to account for the final fps reported.

Removing the fps counter does not change the results in the profiler, running without the profiler does not change the fps results.

My questions are:

1. Is this expected behavior for an almost empty project?
2. Why the erratic fluctuation, I expect some overhead, but should it be going up and down by 16ms?

Thanks for any input.

Regards
Matt

 

On watching the FPS longer I see after about 30 seconds it settles down and runs at 42 to 43 fps. The CPU usage for device.present still seems to be the only item in the profiler accounting for the drop in performance.

When I run a release build with no profiler, I still see 42 to 43 fps.

I've disabled the mesh and box collider in the scene. Removed the light, etc. With no noticeable change.

Regards
Matt

 

Running on windows phone 8

I get 59 to 60 fps and Graphics.PresentAndSync -> Device.Present 0ms taking 0% of the cpu.

I'm confused why I don't see this result on Android.

 

Ok, interestingly the same build deployed to an older device does not exhibit the same issue.

Samsung Galaxy S2 phone
- 1.2 Dual Core Processor
- 1 Gig RAM
- 800 x 600 Screen Rez

Idles around 59 to 60 fps and about 12ms cpu, Graphics.PresentAndSync -> Device.Present 0.87ms

So at this stage it seems perhaps the GPU on the Samsung Galaxy Tab (Vivante GC1000) is presenting an issue not present in the other devices.

 

I've observed the same behaviour on my tablet:
- Rockchip RK3188 (Quad-core ARM Cortex-A9, Mali-400 MP4)
- Android 4.2.2
- 2048x1536
- 44 fps (only camera)

 

You found any answer? I have the same problem

 

It's the Mali-400 MP4 chip. They aren't the greatest. You want a MP 450 or newer quad core GPU. And you want Android 4.4.4 or newer. And you want 1024 RAM.

 

I have the problem in Motorola G 1st and 2gn. Also in other devices

 

The very same on Motorola Xoom 2 ME, and PMP5570c tablets. However all runs smoothly on LG g2 mini. My opinion it is graphic adapter drivers compatibility issue.

Update: for me it is likely Lightmap. I disabled lightmap and set lights to not cast shadows -> fps doubled. But it was baked lightmap, what's the point?

Update: It was not lightmap issue, but if you have lightmap, you should turn off shadow on all your lights, otherwise game will slow down on mobile

 

I found the problem, on my case the problem was l had too much draw calls with the new ui. I think the profiler need improve tho show better information.

 

I have a similiar problem on Android only. iOS is fine. I'm adaptively disabling a couple of image effect based on the current FPS by first disabling the image effect component and then destroying the component (so they won't blit from src to dest) every update anymore.

With the effects enabled, the Graphics.PresentAndSync node shows a child Device.Present with taking an average of 43.9% of the CPU time on a Moto G2. As a child this node has Present.BlitToCurrentFB. I don't know if this is rendering to screen or the copying of the src rendertexture to the destination rendertexture in the OnRenderImage callbacks of the image effects. I somewhat expected this to happen on GPU and not on CPU though.

Anyway, if I disable the effects at runtime, the performance is worse than when running the same build without the image effects in the first place. There are up to 15 frames/s missing. There are regular spikes of Device.Present and Present.BlitToCurrentFB. This drives me nuts. I don't understand why there is a performance overhead when the image effects scripts and OnRenderImage callbacks are not present anymore. This seems to happen only on Android with Unity 5.0.1f.

Any ideas?

P.S.: You should stop scaling quality settings by just disabling the image effect scripts at runtime like most "solutions" in the forum suggest. The OnRenderImage callback that copies from the source rendertexture to the destination rendertexture is still called when the script is disabled!