Negative value on mac m3 with webgpu

[Makio64]

I got negative value for the GPU time while checking last commits/examples update on threejs release164.

I know webgpu is fast but this seems too fast haha :D

Device : macbook pro m3 max
OS : MacOs latest
Browser : Chrome latest

[RenaudRohlinger]

m3 max too stronk.

Unexpected indeed, will check.😁

[Makio64]

Hi @RenaudRohlinger , do you need help to investigate this issue and calm down the m3 max ? :D

The calculation from here seem correct : https://webgpu.github.io/webgpu-samples/?sample=bundleCulling

[RenaudRohlinger]

Even with my M1 Max Pro and iPhone 12, I am unable to reproduce this issue, nor the one described in #11.

Without encountering these bugs myself, it's difficult for me to diagnose and fix the issue. Could you clarify if the problem seems to originate from the Three.js side or the stats-gl side?

You can try logging the values with console.log(gl.info.render.timestamp) in the examples to confirm this. /cc @Makio64.

[Makio64]

This console.log return me : gl is undefined
I cloned three.js and changed the example of batch adding some log on stats.gl but its always null
Your example https://stats.renaudrohlinger.com/ works as expected ( bellow screenshot )

[Makio64]

The problem is still present on latest version ( macos chrome )

low power mode screenshot :

normal mode :

On safari it didnt display gpu informations even the webgpu mode is enabled, should i enabled other extension ?

[Makio64]

also didnt display on safari webgpu enabled on iOS

[darrinm]

I'm also seeing negative numbers (macOS Chrome, Mac Studio M2 Ultra):

[Makio64]

Hello, just retried today, and the value are still negative in threejs examples but positive in the webgl example.

Looking forward your recent works on threejs gpu timestamp to be reflected on this lib 👍

[Makio64]

Just tested on a personal project and it seems to work with rendererAsync and r172 🤟

[RenaudRohlinger]

Nice! Could you try this example that uses the new TimestampQueryPool API see how it goes? @Makio64:

https://rawcdn.githack.com/mrdoob/three.js/dev/examples/webgpu_compute_particles_snow.html

[Makio64]

@RenaudRohlinger got negative value :(

[RenaudRohlinger]

I have exactly around 10.5ms with my M1 Max, I'm pretty sure that's a GPU Metal issue then, but the numbers seems more than accurate there. I might just end up Math.abs() in the tool then.

[RenaudRohlinger]

r172 only output the last query and wasn't accurate, which is why I ended up working on mrdoob/three.js#30359 to stabilize everything. I'm pretty confident with this new version and I don't think the code can output negative values on the threejs side. Maybe it's a stats-gl issue, did you had the same issues with r3f-perf?

[Makio64]

Value seems correct on r3f-perf ( also as i mentionned it's seems correct on my current r172 project + stats-gl )

[Makio64]

sorry to bother you.. i just update from r172 to latest dev ( following your comment on .toConst implemented in dev ) and now i got this result, r172 was working :

[RenaudRohlinger]

You need to call resolveTimestampsAsync after (not need to await)

mrdoob/three.js#30359 (comment)

[Makio64]

Seems to work! I now got a value between 2 and -1 ( rarely )

		await this.renderer.renderAsync( this.scene, this.camera ) // await necessary else negative value output
		this.renderer.resolveTimestampsAsync( TimestampQuery.RENDER );
		this.stats.update()