Godot runs slower with GLES2 than GLES3

[sdfgeoff]

Godot version:
Recent master:
2605837

OS/device including version:
OS: Ubuntu 18.04 with many things removed for performance
Hardware: Intel Atom x5-8350, 2Gb ram. Integrated GPU ("HD Graphics (Cherry Trail)")

Issue description:
Yes, I'm aware that this is a very low spec piece of hardware. I was not expecting it to run well, and actually, the fact that Godot ran at all was a pleasant surprise. The other surprise was:

• When running with --video-driver GLES3 --print-fps the result is around 34 FPS
• When running with --video-driver GLES2 --print-fps the result is around 18 FPS

Description of the scene:

• One directional lamp with shadow
• About 10-20 objects, all with "normal" spatial shaders. Two materials have a single texture.
• A GUI

I'm not sure if this is an issue, or if it's just myself misunderstanding the purpose of GLES2 mode, so:
Should GLES2 have better performance than GLES3

[volzhs]

#24466 pointed it too

[akien-mga]

Can you try before bec76cf?

[sdfgeoff]

No difference with 3c999ae FPS is still slower on GLES2

[OBKF]

I also have noticed a drop in FPS and a high CPU usage when using the GLES2 (not always) compared to GLES3. Godot2 was way too fast for 3D, I thought it was because Godot3's GLES2 looks better.
I also have noticed that using multithreading causes more lag even if you get 10-40 FPS.

[avril-gh]

on this 1039ba9 and before, i seen 50-55 FPS on android GLES2 devices, and above 1000 FPS on PC
after this #24445 has been fixed i noticed FPS has drop to 9-10 FPS on android and 350-450 FPS on PC.
(you can see on video there 40-50 FPS due to recording. Usualy its been 55 FPS or more)

Godot2 was way too fast for 3D

Well, not that fast. In some cases im geting there on android frame rate drop to 15-20 FPS,
but its very stable and works good even on exotic devices.
Godot2 GLES2 driver is good, thats why im still using it.

[reduz]

There are plenty of scenarios where GLES2 runs slower than GLES3, so this is not a surprise and it's completely to be expected. The opposite is also true.

I am closing this because there are no specifics given.

If you have a specific use case where you believe GLES2 should be faster than GLES3, and want to submit a test project, feel free to open a new issue.

[sdfgeoff]

Um, this is a single directional lamp with a shadow. I do not agree that that should run slower.
I'll make a test case tomorrow.