Graphics profiler GFX.WaitForCommands, What is does it mean?

Unity Engine
1

I get some long frames when rendering on Android.

On these long frames GFX.WaitForCommands() appears on the Rendering thread and I’m wondering what it is and why it might happen.

The difference between a short and long frame is 6ms for rendering and 26ms for rendering.

Any advice would be helpful.

Profiler screenshot attached.

Slow frame with lots of GFX.WaitForCommands() calls (the grey boxes down the bottom)

3474674--276131--Screen Shot 2018-04-26 at 10.33.17 AM.png
3474674--276131--Screen Shot 2018-04-26 at 10.33.17 AM.png2804×1782 427 KB

Fast frame with almost no GFX.WaitForCommands() calls.

3474674--276132--Screen Shot 2018-04-26 at 10.34.15 AM.png
3474674--276132--Screen Shot 2018-04-26 at 10.34.15 AM.png2380×1778 362 KB

2

Hi!
It means that the thread that submits commands to the GPU is waiting for stuff to do.

3

Ok, so the CPU thread is bound in this case and not sending commands to the render thread fast enough?

4

Yes, looks like it.

5

@Nouman_Maqbool you can try to do less things on the CPU or do them faster.

6

There’s a lot of resources about CPU frame time optimisation for Unity.