High CPU usage in bufferSubData on Safari (v5.32.1)

Questions
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1

Hi guys,

Suddenly I’m getting really slow frame rates on mobile (iPhone XS, iOS 16.1). Most of the time is spent in bufferSubData in engine.uniformBuffer, and engine.dynamicBuffer.

Screenshot 2022-11-15 at 12.11.45 PM
Screenshot 2022-11-15 at 12.11.45 PM1511×279 58.8 KB

It’s a simple scene, all materials are standard, and everything is very low-poly. Runs without breaking a sweat on Chrome, but very slow on Safari - can’t hit 60 fps even on MacBook Pro, and single digits on iPhone.

Screenshot 2022-11-15 at 12.20.42 PM
Screenshot 2022-11-15 at 12.20.42 PM884×430 307 KB

I swear this used to hit 60 fps on the phone… Maybe a recent change in the engine?

UPDATE: After setting engine.disableUniformBuffers, Safari performance is fine, even on a phone.

2

Can you try to turn off webgl2 maybe?

3

I am wondering if they suffer from the Same than Chrome on MacOS as they now use a angle backend… @Deltakosh do you want me to flag Safari to disable UBO as well ? I thought this would be fixed when angle would turn the metal backend on ?

4

If this is the cause: OH YEAH!

1 Like
6

@alekop can you share a repro ? so that I can validate my fix ?

7

I didn’t turn off WebGL2, but disabling UBO on Safari solved the issue.

8

I can’t find a PG that shows this issue. What’s the fix? If it’s turning off UBO on Safari, I’m already doing that, so it should be fine.

9

Could you share your experience or something I could use to validate the fix ? as currently I am not able to repro and I do not want to turn it fully off for everyone if it is not faster in the majority of cases.