high cpu-waits-gpu on iPad

[dilshod]

Hi,

I have a simple scene, all standard ngui sprites, 3 panels and 60-70 sprites, not so many draw calls and verts/tris, no special shaders, no post processing shaders, no clipping panels.
Why cpu-waits-gpu time is so high? Value changes over time, some times it is 0, some times it is 3-4.
On 60 fps, i can see some motion lags when cpu-waits-gpu is greater than 1. Testing on iPad mini 2, iOS 8.

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iPhone Unity internal profiler stats:
cpu-player>    min:  8.4   max: 10.6   avg:  9.2
cpu-ogles-drv> min:  0.5   max:  1.3   avg:  0.5
cpu-present>   min:  4.5   max:  9.4   avg:  6.7
cpu-waits-gpu> min:  4.5   max:  9.4   avg:  6.7
 msaa-resolve> min:  0.0   max:  0.0   avg:  0.0
frametime>     min: 14.2   max: 19.5   avg: 16.6
draw-call #>   min:  12    max:  12    avg:  12     | batched:     0
tris #>        min:   466  max:   466  avg:   466   | batched:     0
verts #>       min:   932  max:   932  avg:   932   | batched:     0
player-detail> physx:  0.2 animation:  0.0 culling  0.0 skinning:  0.0 batching:  0.0 render:  2.3 fixed-update-count: 0 .. 1
mono-scripts>  update:  3.4   fixedUpdate:  0.0 coroutines:  0.0
mono-memory>   used heap: 7618560 allocated heap: 8036352  max number of collections: 0 collection total duration:  0.0
----------------------------------------

[ArenMook]

Because your framerate is higher than 60 fps, and the device has to wait?

[dilshod]

Because your framerate is higher than 60 fps, and the device has to wait?

Nope, it is 60 fps, it's not higher.
I think it has some input lags, maybe touches priority is low. Because when i move objects with a tween, it moves smoothly, but when i drag objects by hand moves are not smooth.

As it is said on page http://docs.unity3d.com/Manual/iphone-iOS-Optimization.html

Conversely, you can increase the framerate to give the rendering priority over other activities such as touch input and accelerometer processing.

[dilshod]

I fixed motion lag by smoothing drag delta. I just did something like this:

1. Vector2 totalDelta, targetTotalDelta;
2.  
3. void OnDragStart() {
4.   totalDelta = Vector2.zero;
5.   targetTotalDelta = Vector2.zero;
6.   dragging = true;
7. }
8.  
9. void OnDrag() {
10.   targetTotalDelta = UICurrent.currentTouch.totalDelta;
11. }
12.  
13. void Update() {
14.   if (dragging) {
15.     totalDelta = Vector2.Lerp(totalDelta, targetTotalDelta, 0.25f);
16.     // ...
17.   }
18. }
19.