Unexpected bad performance

[tzlils]

Bevy version

0.6

Operating system & version

Windows 10.0.19043 Build 19043

What you did

Compiled and ran the many_cubes example with opt-level=3 in debug mode and release mode

What you expected to happen

The 3D scene is rendered at my monitor's refresh rate (60.056)

What actually happened

Surprisingly low FPS

Additional information

bevy_render::renderer: AdapterInfo { name: "Intel(R) UHD Graphics", vendor: 32902, device: 35414, device_type: IntegratedGpu, backend: Vulkan }

the FPS was about the same in release and in debug mode, it was not affected by turning off vsync

[alice-i-cecile]

Could you check your FPS on some other examples? 2D would be nice to compare against, as would the web examples https://bevyengine.org/examples/ (bevymark for example has an FPS counter).

[tzlils]

seeing stable 60 fps on bevymark,
drops to 20 FPS at around 52k birds.

compiling and running the many_sprites example on release with opt-level=3 and getting 24 FPS average

[GioPat]

I'm having a similar (using alien cake addict example) issue: #3027 (comment)

I'm keen to do further tries if you need!

[superdump]

Could you all try with WGPU_OPTIONS_PRIO=compatibility to see if that makes a difference? I'm trying to find cases where #3686 has observable practical impacts and this could be one.

[GioPat]

Tried running with this command, setting WGPU_OPTIONS_PRIO as env variable:

set WGPU_OPTIONS_PRIO=compatibility&& cargo run --example alien_cake_addict --release

I have an improvement of ~10 FPS: Now running at 44/45 FPS

[superdump]

Perfect, thanks. Others experiencing unexpectedly poor performance are welcome to test too as it is interesting to hear if all cases are due to #3686 or if there are other issues to be addressed.

[GioPat]

Also run the bevymark test as advised by @alice-i-cecile these are the results:

Debug
Hitting 15FPS @ 15000 Birds 🐦

Release with no WGPU_OPTIONS_PRIO
Hitting 10 FPS @ 78000 Birds 🐦

Release with WGPU_OPTIONS_PRIO=compatibility
Hitting 10 FPS @ 78000 Birds 🐦 (same as the previous test)