GPUAdapter.limits seems unable to detect the true capabilities of the GPU

[microaaron]

The GPUSupportedLimits obtained by Chrome(dawn) and Firefox(wgpu) are not consistent.
And the capabilities of modern GPUs are obviously higher than these data.
This data appears to be fixed in the software rather than being read from the hardware. And it's set very conservatively.(e.g. maxUniformBuffersPerShaderStage, maxVertexBuffers...)
This makes it difficult to convert some webgl programs into webgpu programs

[Kangz]

This is completely expected. Browser can expose any limits lower than what the hardware supports, and for a variety of reasons. They are required to bucket limits and features to limit the amount of fingerprinting exposed, they could have implementation limits (for example maxBindGroups:4 in Chromium at the moment), and any other reason.

It would be useful to know what limit is making it difficult to port your WebGL code so we could suggest a workaround, or add some new buckets in implementations.

[microaaron]

I encountered the problem that Chrome's maxUniformBuffersPerShaderStage and maxVertexBuffers are too small when porting WebGL codes.
I think webgpu should somehow get the full capabilities of the hardware to maximize the performance of the GPU.
As for inferring fingerprinting based on GPU capabilities, I think it is meaningless, because Webgl's API can completely obtain detailed GPU information.

[Kangz]

What values do you get in Chromium for these in WebGL / WebGPU and what values do you need?

[microaaron]

For maxUniformBuffersPerShaderStage and maxVertexBuffers, I hope Chromium provides at least the same values as firefox.
Firefox provides 64 UniformBuffersPerShaderStages and 16 VertexBuffers. Chromium only provides 12 and 8.
Of course, this may still not meet future needs

[greggman]

It's been brought up before for maxVertexBuffers to make the default be 16 to match WebGL2

#4284

maxUniformBuffersPerStage it doesn't seem like we could raise the default but certainly various browsers could look into raising the limit when supported.

[microaaron]

maxUniformBuffersPerStage it doesn't seem like we could raise the default but certainly various browsers could look into raising the limit when supported.

I don't expect to raise the default value. The default value should be set conservatively to be compatible with older hardware. But the browser should be able to detect the maximum capabilities of the GPU. Currently Chromium can only support default values, and Firefox can pass requiredLimits in requestDevice() to support larger values.